Product Description
5/8" UNF Part-Threaded High Tensile Socket Cap Bolts
5/8"-18 UNF socket head cap bolts manufactured from heat-treated high tensile alloy steel, with a self colour, unplated finish. These part-threaded bolts feature a plain shank beneath the cylindrical cap head and a 1/2" internal hexagon drive.
The fine UNF thread suits matching imperial nuts and tapped components. The unthreaded shank provides a plain section through the assembly, making these bolts useful for machinery, engineering repairs and maintenance applications requiring a part-threaded fastening.
Specifications
| Product type | Part-threaded socket head cap bolt |
|---|---|
| Nominal thread diameter | 5/8" – 15.875mm |
| Thread type | UNF – Unified National Fine |
| Threads per inch | 18 TPI |
| Thread direction | Right-hand |
| Material | Heat-treated high tensile alloy steel |
| Material specification | ASTM A574 |
| Finish | Self colour / plain, unplated |
| Head style | Cylindrical socket cap head |
| Drive type | Internal hexagon socket |
| Allen key size | 1/2" |
| Thread coverage | Part-threaded, with a plain shank |
| Length measurement | From underneath the head to the bolt tip |
Available Lengths
| Imperial length | Metric equivalent |
|---|---|
| 2 1/2" | 63.50mm |
| 2 3/4" | 69.85mm |
| 3" | 76.20mm |
| 3 1/4" | 82.55mm |
| 3 1/2" | 88.90mm |
| 3 3/4" | 95.25mm |
| 4" | 101.60mm |
| 4 1/2" | 114.30mm |
| 5" | 127.00mm |
| 5 1/2" | 139.70mm |
| 6" | 152.40mm |
| 6 1/2" | 165.10mm |
| 8" | 203.20mm |
Key Features
- High tensile alloy steel to ASTM A574.
- 5/8"-18 UNF fine thread.
- Part-threaded design with a plain shank beneath the head.
- Socket cap head with a 1/2" Allen key drive.
- Thirteen available lengths from 2 1/2" to 8".
Selection and Installation
Use with matching 5/8"-18 UNF nuts or tapped holes. Check both the overall length beneath the head and the required threaded engagement. Thread and shank lengths vary with bolt length; confirm these dimensions before ordering where the shank position is critical.
Fully engage the 1/2" hex key and tighten to the torque specified for the assembly. Apply suitable corrosion protection where the plain, unplated finish requires it.
Pack Sizes
Available in packs of 1, 5, 10, 20, 50 and 100. Select the required length and pack quantity from the options.
Standards
- ASME B18.3 – imperial socket head cap screw dimensions.
- ASTM A574 – alloy steel socket head cap screw specification.
- ASME B1.1 – Unified inch thread reference.
