3,575 Piece Grade 8 UNC Hex Head Cap Screw Assortment Starter Kit
When vibration is a constant — compressors, generators, trailers, trucks, heavy equipment — nylon-insert lock nuts provide a reliable mechanical grip that won't back off between maintenance windows. This 3,575-piece Grade 8 UNC assortment covers 1/4"-20 through 3/4"-10 across eight diameters, including hex head cap screws, hex nuts, nylon-insert lock nuts (Grade C), USS flat washers, and high-alloy lock washers, stored in two labeled 40-hole metal bins.
What's Included
- Grade 8 hex head cap screws — 1/4"-20 through 3/4"-10 UNC, multiple lengths per diameter
- Grade 8 hex nuts — matching every bolt diameter in the kit
- Nylon-insert lock nuts (Grade C) — matching every bolt diameter, for vibration-resistant fastening rated to 250°F continuous
- USS flat washers and high-alloy lock washers — one set per diameter
- Two 40-hole metal bins — shipped in separate boxes to protect the bins in transit
- 3,575 pieces total
Specifications
| Thread standard | UNC — Unified National Coarse |
| Grade | SAE J429 Grade 8 |
| Tensile strength | 150,000 PSI minimum |
| Finish | Yellow zinc |
| Diameters | 1/4"-20, 5/16"-18, 3/8"-16, 7/16"-14, 1/2"-13, 9/16"-12, 5/8"-11, 3/4"-10 |
| Lock nut type | Nylon-insert (Grade C) — rated to 250°F continuous |
| Total pieces | 3,575 |
| Approx. weight | ~90 lbs |
| Storage | Two 40-hole metal bins (80-hole total) |
| SKU | ASST80C8/NLNC8 |
Best For
- Vibration-prone equipment — compressors, generators, truck beds, trailers, and agricultural machinery where fasteners must stay put between service intervals
- Fleet maintenance facilities — stocking Grade 8 UNC across the full 1/4" through 3/4" range without managing individual SKUs
- Construction and heavy equipment repair — high-strength coarse-thread bolting for structural connections and major assemblies
- In-plant maintenance departments — a complete Grade 8 UNC inventory across 8 diameters, ready to pull from daily
- Multi-person shops — enough volume across the full diameter range to keep multiple jobs stocked simultaneously
About Grade 8
Grade 8 is the highest-strength SAE fastener grade commonly stocked in repair and industrial environments. At 150,000 PSI minimum tensile strength, it's the right choice for high-stress structural connections, heavy equipment assembly, and anywhere Grade 5 isn't enough. Yellow zinc finish provides corrosion resistance for indoor shop storage and outdoor or under-hood applications. UNC coarse thread is the standard for most structural and heavy-duty applications — faster to assemble than fine thread and less prone to cross-threading in field conditions.
Nylon-insert lock nuts are the most widely stocked vibration-resistant nut for applications up to 250°F continuous. If your equipment runs hotter than that — exhaust systems, engine bays, heat treat fixtures, or powder coat racks — see our Grade 8 UNC Starter Kit with All-Steel Lock Nuts, which carries the same full 3,575-piece assortment with temperature-rated all-steel prevailing-torque lock nuts.
Starter Kit vs. Refill — Which Do I Need?
| Starter Kit | Refill | |
| Fasteners (3,575 pcs) | ✓ | ✓ |
| Nylon-insert lock nuts (Grade C) | ✓ | ✓ |
| Two 40-hole metal bins | ✓ Included | — Already own them |
| QR-coded labels | ✓ Included | — Already have them |
If this is your first purchase, the Starter Kit includes the bins, labels, and the full fastener load — everything needed to get organized from scratch. If you already own a set of 40-hole bins from a previous kit purchase, the Grade 8 UNC Nylon Lock Nut Refill restocks them completely without paying for storage you already have.
Shipping & Ordering
- Ships within 1–2 business days from our warehouse
- Ships in separate boxes to protect the bins in transit
- Volume pricing available — save up to 20% when ordering 3 or more kits
- B2B accounts: Fleet managers, facilities teams, and machine shops can apply for a business account with custom pricing and a dedicated rep — contact us to get started