Product Description
3/8" UNF Grade 8 Hexagon Head Bolts – Yellow Zinc Plated, 24 TPI
These 3/8" UNF hexagon head bolts are manufactured from SAE Grade 8 high tensile alloy steel with a yellow zinc plated finish. They feature a 24 TPI Unified National Fine thread and are available in imperial lengths from 1 1/2 inches to 6 inches.
All available lengths are partially threaded, with a plain shank beneath the head. The hexagon head accepts a 9/16" spanner or socket for installation and removal.
Key Features
- SAE Grade 8: High tensile alloy steel for demanding mechanical fastening applications.
- 3/8" UNF thread: Fine imperial thread with 24 threads per inch.
- Partially threaded: Plain shank beneath the head on every available length.
- Yellow zinc plated finish: Provides additional corrosion protection compared with unplated steel.
- Hexagon head: Uses a 9/16" spanner or socket.
- Choice of lengths: Select the required bolt length and pack quantity from the available options.
Technical Specifications
| Product Type | Hexagon head bolt with plain shank |
|---|---|
| Thread Size | 3/8" UNF |
| Nominal Thread Diameter | 3/8 inch – 9.525mm |
| Threads Per Inch | 24 TPI |
| Thread Type | Unified National Fine |
| Material | High tensile alloy steel |
| Strength Grade | SAE Grade 8 |
| Mechanical Standard | SAE J429 Grade 8 |
| Dimensional Standard | ANSI B18.2.1 |
| Finish | Yellow zinc plated |
| Head Style | Hexagon |
| Spanner / Socket Size | 9/16 inch |
| Thread Coverage | Partially threaded on all available lengths |
| Length Measurement | Measured from beneath the head to the end of the bolt |
Available Bolt Lengths
| Imperial Length | Metric Equivalent |
|---|---|
| 1 1/2 inches | 38.1mm |
| 1 3/4 inches | 44.45mm |
| 2 inches | 50.8mm |
| 2 1/4 inches | 57.15mm |
| 2 1/2 inches | 63.5mm |
| 2 3/4 inches | 69.85mm |
| 3 inches | 76.2mm |
| 3 1/4 inches | 82.55mm |
| 3 1/2 inches | 88.9mm |
| 4 inches | 101.6mm |
| 4 1/2 inches | 114.3mm |
| 5 inches | 127mm |
| 5 1/2 inches | 139.7mm |
| 6 inches | 152.4mm |
All lengths use the same 3/8" UNF thread with 24 TPI. Metric equivalents are conversions of the stated imperial lengths.
Typical Applications
- Machinery and equipment assembly.
- Vehicle repairs where 3/8" UNF Grade 8 bolts are specified.
- Securing brackets, housings and mechanical components.
- Maintenance and replacement of matching imperial fine-thread bolts.
Selecting Your Bolts
Match the 3/8" UNF diameter and 24 TPI thread to the mating nut or tapped hole. Select a length that accommodates the components being joined and provides sufficient thread engagement.
Allow for the plain shank when selecting a partially threaded bolt, particularly when fastening into a tapped hole. Use compatible high-strength nuts and washers, and follow the tightening requirements for your assembly.
Select your required bolt length and pack quantity from the available options. Browse our nuts for matching fastening options, or visit our thread data guide to compare imperial thread sizes and pitches.
