Product Description
5/16″-18 UNC Zinc Plated Countersunk Socket Bolts – Part Threaded
5/16″-18 UNC countersunk socket bolts manufactured from high tensile alloy steel with a zinc plated finish. These part-threaded bolts feature a plain shank and an 82° flat countersunk head for flush seating in a matching countersink.
The internal hexagon socket accepts a 3/16″ Allen key. Available in three lengths for compatible machinery, equipment assembly, repairs and maintenance.
Specifications
| Thread size | 5/16″-18 UNC |
|---|---|
| Nominal thread diameter | 5/16″ / 7.9375mm |
| Threads per inch | 18 TPI |
| Thread series | Unified National Coarse, right-hand |
| Material | High tensile alloy steel grade 8 |
| Mechanical specification | ASTM F835 |
| Finish | Zinc plated |
| Head style | Flat countersunk socket head |
| Head angle | 82° included angle |
| Drive size | 3/16″ hexagon socket / Allen key |
| Thread coverage | Part threaded with a plain shank |
| Available lengths | 2″, 2 1/4″ and 2 1/2″ |
| Length measurement | Overall length, including the countersunk head |
Available Lengths
- 5/16″-18 UNC × 2″
- 5/16″-18 UNC × 2 1/4″
- 5/16″-18 UNC × 2 1/2″
Key Features
- High tensile alloy steel construction.
- Zinc plated finish provides corrosion protection.
- Part-threaded design incorporates a plain shank.
- 82° countersunk head for flush seating in a matching countersink.
- Internal hexagon drive accepts a 3/16″ Allen key.
Selection and Installation
Check that the mating thread is 5/16″-18 UNC. These bolts are not interchangeable with 5/16″-24 UNF or metric threads.
Measure the required length including the countersunk head. Check that the plain shank and threaded portion suit the joint thickness and provide sufficient thread engagement. Exact shank and thread lengths are not specified.
Use a matching 82° countersink, seat the correct Allen key fully and tighten to a torque appropriate to the joint and mating material.
Pack Sizes
Available in quantities of 1, 5, 10, 20, 50 or 100 bolts. Select the required length and pack size before ordering.
Standards
- ASME B18.3 – imperial socket screw dimensions.
- ASTM F835 – alloy steel socket flat countersunk head cap screw mechanical specification.
- ASME B1.1 – Unified inch screw threads.
