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Cap Head Seal Screws with Under Head Seal

SKU: SF12 Categories: ,

Cap Head Seal Screws with Under Head Seal are designed to prevent the leakage of fluids and gases under pressure, offering an alternative to the use of traditional gaskets.

Featuring a highly durable under head seal, this reusable sealing solution prevents galvanic corrosion between dissimilar materials, while offering excellent resistance to a wide range of automotive fluids and chemicals – including alcohol, gasoline, kerosene, oil, diesel fuel and hydraulic fluids.

The green seal is permanently fused to the bearing surface of fastener and does not shrink or dry out over time. During installation, it compresses to fill the space between the bearing surface of the head and the counter bore. Special coloured seals are available on request.

Cap Head Seal Screws with Under Head Seal are more cost-effective compared to standard o-ring seal screws and can be supplied with a much shorter lead time. They are available with either a Socket drive, typically to DIN 912 standard / ISO 4762 / ASME B18.3, or a 6 Lobe TX drive, typically to ISO 14579.

The seal can be applied to all of our standard materials, including Steel and Stainless Steel, with non-standard materials and finishes available on request.

Available at Fastenright in thread sizes M1.4 to M30. UNC / UNF threads are also available.

Non-standard sizes, materials and finishes are available to order as specials, including small volume manufacture, modifications and bespoke parts made to drawings. Minimum order quantities apply.

Our full range of Sealing Fasteners can be found here.

Cap Head Seal Screws with Under Seal Head Technical Drawing

M10 to M30

M1.4 to M8 Technical Data & Availability
Thread
Diameter (d)
M1.4 M1.6 M2 M2.5 M3 M3.5 M4 M5 M6 M8
dk max. (mm) 2.6 3 3.8 4.5 5.5 6 7 8.5 10 13
k max. (mm) 1.4 1.6 2 2.5 3 3.5 4 5 6 8
b (mm) 14 15 16 17 18 20 20 22 24 28
Available
Lengths (L)
M1.4 M1.6 M2 M2.5 M3 M3.5 M4 M5 M6 M8
2mm black icon imagered icon image
3mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
4mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
5mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
6mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
8mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
10mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
12mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
14mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
16mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
18mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
20mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
22mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
25mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
30mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
35mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
40mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
45mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
50mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
55mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
60mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
65mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
70mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
75mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
80mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
85mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
90mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
95mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
100mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
110mm black icon imagered icon image black icon imagered icon image black icon imagered icon image
120mm black icon imagered icon image black icon imagered icon image black icon imagered icon image
130mm black icon imagered icon image black icon imagered icon image black icon imagered icon image
140mm black icon imagered icon image black icon imagered icon image black icon imagered icon image
150mm black icon imagered icon image black icon imagered icon image
160mm black icon imagered icon image black icon imagered icon image
170mm black icon imagered icon image black icon imagered icon image
180mm black icon imagered icon image black icon imagered icon image
190mm black icon imagered icon image black icon imagered icon image
200mm black icon imagered icon image black icon imagered icon image
210mm red icon image black icon imagered icon image
220mm red icon image black icon imagered icon image
230mm black icon imagered icon image
240mm black icon imagered icon image
250mm black icon imagered icon image
260mm black icon imagered icon image
270mm black icon imagered icon image
280mm black icon imagered icon image
290mm black icon imagered icon image
300mm black icon imagered icon image
black icon image = A2 / 304 Stainless Steel // red icon image = A4 / 316 Stainless Steel
Size not listed? Please make an enquiry – we may be able to provide it.

No.0 to No.12

M10 to M30 Technical Data & Availability
Thread
Diameter (d)
M10 M12 M14 M16 M18 M20 M22 M24 M27 M30
dk max. (mm) 16 18 21 24 27 30 33 36 40 45
k max. (mm) 10 12 14 16 18 20 22 24 27 30
b (mm) 32 36 40 44 48 52 56 60 66 72
Available
Lengths (L)
M10 M12 M14 M16 M18 M20 M22 M24 M27 M30
12mm black icon imagered icon image
14mm black icon imagered icon image
16mm black icon imagered icon image black icon imagered icon image
18mm black icon imagered icon image black icon imagered icon image
20mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
22mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
25mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
30mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
35mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
40mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
45mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
50mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
55mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
60mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
65mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
70mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
75mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
80mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
85mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
90mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
95mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
100mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
110mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
120mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
130mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
140mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
150mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
160mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
170mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
180mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
190mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
200mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
210mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
220mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
230mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
240mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
250mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
260mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
270mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
280mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
290mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
300mm black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image
black icon image = A2 / 304 Stainless Steel // red icon image = A4 / 316 Stainless Steel
Size not listed? Please make an enquiry – we may be able to provide it.

1/4″ to 1″

ASME B18.3 UNC / UNF Technical Data & Availability
Thread
Diam.
(d)
0-80
UNF
1-64
UNC
1-72
UNF
2-56
UNC
2-64
UNF
3-48
UNC
3-56
UNF
4-40
UNC
4-48
UNF
5-40
UNC
6-32
UNC
6-40
UNF
8-32
UNC
8-36
UNF
10-24
UNC
10-32
UNF
12-24
UNC
dk max
(in)
0.096 0.118 0.118 0.140 0.140 0.161 0.161 0.183 0.183 0.205 0.226 0.226 0.270 0.270 0.312 0.312 0.343
k max
(in)
0.060 0.073 0.073 0.086 0.086 0.099 0.099 0.112 0.112 0.125 0.138 0.138 0.164 0.164 0.190 0.190 0.216
b max
(in)
0.99 0.99 0.99 0.99 0.99 0.99 0.99 0.99 0.99 1 1.05 1.05 1.19 1.19 1.27 1.27 1.27
Avail.
Lengths
(L)
0-80
UNF
1-64
UNC
1-72
UNF
2-56
UNC
2-64
UNF
3-48
UNC
3-56
UNF
4-40
UNC
4-48
UNF
5-40
UNC
6-32
UNC
6-40
UNF
8-32
UNC
8-36
UNF
10-24
UNC
10-32
UNC
12-24
UNC
3/32″ black icon image
1/8″ black icon image black icon image black icon image black icon image black icon image black icon image black icon image black icon image black icon image
5/32″ black icon image black icon image black icon image black icon image black icon image black icon image black icon image black icon image black icon image
3/16″ black icon image black icon image black icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon image black icon image black icon image black icon image black icon image
7/32″ black icon image black icon image black icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon image black icon image black icon image black icon image black icon image
1/4″ black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image
5/16″ black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image
3/8″ black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image black icon image
7/16″ black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image black icon image
1/2″ black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image black icon image
9/16″ black icon image black icon image black icon image black icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image black icon image
5/8″ black icon image black icon image black icon image black icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image black icon image
3/4″ black icon image black icon image black icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image black icon image
7/8″ black icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image black icon image
1″ black icon image black icon image black icon image black icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image black icon image
1 1/8″ black icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon image
1 1/4″ black icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon image
1 3/8″ black icon image black icon image black icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon image
1 1/2″ black icon image black icon image black icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon image
1 3/4″ black icon image black icon image black icon image black icon imagered icon image black icon imagered icon image
2″ black icon image black icon image black icon image black icon imagered icon image black icon imagered icon image
2 1/4″ black icon image black icon image black icon image black icon image
2 1/2″ black icon image black icon image black icon image black icon image
2 3/4″ black icon image black icon image black icon image black icon image
3″ black icon image black icon image black icon image black icon image
3 1/4″ black icon image black icon image black icon image
3 1/2″ black icon image black icon image black icon image
3 3/4″ black icon image black icon image black icon image
4″ black icon image black icon image black icon image
5″ black icon image black icon image
6″ black icon image black icon image
8″
black icon image = A2 / 304 Stainless Steel // red icon image = A4 / 316 Stainless Steel
Size not listed? Please make an enquiry – we may be able to provide it.

 

ASME B18.3 UNC / UNF Technical Data & Availability
Thread
Diam.
(d)
1/4-20
UNC
1/4-28
UNF
5/16-18
UNC
5/16-24
UNF
3/8-16
UNC
3/8-24
UNF
7/16-14
UNC
7/16-20
UNF
1/2-13
UNC
1/2-20
UNF
5/8-11
UNC
5/8-18
UNC
3/4-10
UNC
3/4-16
UNF
7/8-9
UNC
1″-8
UNC
dk max
(in)
0.375 0.375 0.469 0.469 0.562 0.562 0.656 0.656 0.75 0.75 0.938 0.938 1.125 1.125 1.312 1.5
k max
(in)
0.25 0.25 0.312 0.312 0.375 0.375 0.438 0.438 0.5 0.5 0.625 0.625 0.75 0.75 0.875 1
b max
(in)
1.5 1.5 1.71 1.71 1.94 1.94 2.17 2.17 2.38 2.38 2.82 2.82 3.25 3.25 3.69 1
Avail.
Lengths
(L)
1/4-20
UNC
1/4-28
UNF
5/16-18
UNC
5/16-24
UNF
3/8-16
UNC
3/8-24
UNF
7/16-14
UNC
7/16-20
UNF
1/2-13
UNC
1/2-20
UNF
5/8-11
UNC
5/8-18
UNC
3/4-10
UNC
3/4-16
UNF
7/8-9
UNC
1″-8
UNC
1/4″ black icon image black icon image black icon image black icon image
5/16″ black icon image black icon image black icon image black icon image
3/8″ black icon imagered icon image black icon image black icon image black icon image black icon image
7/16″ black icon imagered icon image black icon image black icon image black icon image black icon image
1/2″ black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon image black icon image black icon image
9/16″ black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon image black icon image black icon image
5/8″ black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon image black icon image black icon image
3/4″ black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon image black icon imagered icon image black icon image
7/8″ black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image
1″ black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon imagered icon image black icon image black icon image black icon imagered icon image black icon image black icon imagered icon image black icon image black icon image
1 1/8″ black icon imagered icon image black icon imagered icon image