Product Description
5/8"-18 UNF Grade 5 Zinc-Plated Hexagon Set Screws
These 5/8"-18 UNF hexagon-head set screws are manufactured from high-tensile steel with a zinc-plated finish. They provide a fully threaded fastening solution for automotive equipment, machinery, engineering, fabrication, maintenance and general imperial assembly applications.
The 18 threads-per-inch Unified National Fine thread provides finer adjustment and a greater number of engaged threads over a given length than the corresponding 5/8"-11 UNC coarse thread. In UK fastener terminology, a hexagon set screw is threaded along its full usable length beneath the head.
Product Details
- Thread diameter: 5/8"
- Thread designation: 5/8"-18 UNF
- Thread series: Unified National Fine
- Threads per inch: 18 TPI
- Fastener style: fully threaded hexagon-head set screw
- Material: high-tensile steel
- Mechanical grade: SAE Grade 5, subject to manufacturer certification
- Finish: zinc plated
- Spanner size: 15/16" AF
- Nominal head height: 3/8"
- Available lengths: 1 1/4", 1 1/2", 2", 2 3/4" and 3"
Length measurement: Hexagon-head set screw length is measured from beneath the head to the end of the fastener.
Standards Information
- Thread-form reference: ASME B1.1 for Unified inch screw threads
- Dimensional reference: ASME B18.2.1 for inch-series square and hexagon bolts and screws
- Mechanical-property reference: SAE J429 Grade 5, where confirmed by manufacturer certification
These are technically relevant standards, but product conformity should not be claimed unless supported by the manufacturer or supplier’s documentation.
Typical Applications
- Automotive and commercial-vehicle repairs
- Agricultural and construction machinery
- Industrial equipment assembly
- Engineering and fabrication
- Fine-thread adjustment and clamping
- Imperial equipment using 5/8"-18 UNF threads
Installation Guidance
Use with a compatible 5/8"-18 UNF nut or correctly tapped component. Tightening torque must be selected according to the confirmed mechanical grade, joint material, lubrication, zinc coating and application requirements.
Please note: Zinc plating provides moderate corrosion resistance for general indoor and sheltered applications but is not intended for highly corrosive or marine environments. Confirm mechanical properties, dimensions and full thread coverage where these characteristics are critical.
| A | B | C | D | E |
| 5/8" | 1 1/2" | 15/16" | 3/8" | 18 |
| 5/8" | 1 1/4" | 15/16" | 3/8" | 18 |
| 5/8" | 2" | 15/16" | 3/8" | 18 |
| 5/8" | 2 3/4" | 15/16" | 3/8" | 18 |
| 5/8" | 3" | 15/16" | 3/8" | 18 |
Please Note: Specifications given are intended as a guide only. If critical to your project please check with us first.
