Product Description
BSF High Tensile Socket Cap Bolts – Part Threaded – BS 2470
High tensile alloy steel socket cap bolts with British Standard Fine threads and a part threaded shank. The cylindrical head incorporates an internal hexagon socket for tightening with an imperial Allen key.
Suitable for repairs, maintenance and restoration work requiring BSF fasteners. The plain shank beneath the head provides an unthreaded section through the assembled components, where the selected bolt length suits the joint.
Specifications
- Standard: BS 2470:1973
- Material: High-grade alloy steel
- Thread: BSF – British Standard Fine, right hand
- Thread fit: Medium class
- Head: Cylindrical socket cap
- Drive: Internal hexagon, imperial Allen key
- Thread coverage: Part threaded with a plain shank
- Hardness: Rockwell C 39–43
- Tensile strength: 190,000 psi for the sizes listed
- Length measurement: From beneath the head to the end of the bolt
Thread Sizes and Head Dimensions
Dimensions below are in inches. TPI means threads per inch. Head diameter and height are maximum dimensions.
| BSF Thread Size | TPI | Allen Key Size | Maximum Head Diameter | Maximum Head Height |
|---|---|---|---|---|
| 1/4" | 26 | 3/16" | 0.375" | 0.250" |
| 5/16" | 22 | 7/32" | 0.437" | 0.312" |
| 3/8" | 20 | 5/16" | 0.562" | 0.375" |
| 1/2" | 16 | 3/8" | 0.750" | 0.500" |
Available Lengths
Length options across the range: 1 1/2", 1 3/4", 2", 2 1/4", 2 3/4", 3 1/2" and 4". Select your required thread diameter to check the available combinations.
Sizes are shown as thread diameter × length. The head is excluded from the stated length. Plain shank and threaded lengths vary with bolt size; please check before ordering if either dimension is critical.
Quantities
Quantity options: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 50 and 100.
Choosing the Correct Bolt
Match both the thread diameter and TPI to the existing nut or tapped hole. BSF threads are not interchangeable with BSW, UNC, UNF or metric threads. Use the correct imperial Allen key, fully seated in the socket.
Related Products
Browse our nuts, washers and tools and accessories. For help identifying a thread, visit our thread data guide.
