Fine-thread Grade 8 bolts hold tighter under vibration — which is why they're the standard for automotive, aerospace, and precision mechanical applications. This 1,025-piece UNF assortment covers 1/4" through 1/2" fine-thread sizes in a labeled 24-hole metal bin.

What's Included

Grade 8 hex head cap screws — 1/4"-28, 5/16"-24, 3/8"-24, and 1/2"-20, multiple lengths per size
Grade 8 hex nuts — matching every bolt size in the kit
Flat washers and high-alloy lock washers — one set per diameter
24-hole metal bin — pre-labeled and ready to stock
1,025 pieces total

Specifications

Thread standard	UNF — Unified National Fine
Grade	SAE J429 Grade 8
Tensile strength	150,000 PSI minimum
Finish	Yellow zinc
Sizes included	1/4"-28, 5/16"-24, 3/8"-24, 1/2"-20
Total pieces	1,025
Approx. weight	25 lbs
SKU	ASSTHHCS24F8

Best For

Automotive repair — suspension, steering, drivetrain, and engine work where vibration resistance is critical
Aircraft and aerospace maintenance — fine thread is standard in most aviation fastener applications
Precision manufacturing — assembly environments requiring fine torque control and tighter clamping force
Shops building a complete Grade 8 inventory — coarse thread for structural work, fine thread for automotive and precision applications

Fine Thread vs. Coarse Thread

UNF (fine thread) has more threads per inch than UNC (coarse thread), giving it two advantages in the right applications:

Better vibration resistance — more thread engagement means less tendency to loosen under cyclic load
Finer torque adjustment — smaller thread pitch allows more precise clamping force control

Use fine thread for engine and suspension components, steering linkages, precision machinery, and anywhere vibration or repeated disassembly is a factor. Use coarse thread for general structural connections where speed of assembly matters more.

See our Grade 8 UNC Assortment for the coarse-thread companion kit.

Shipping & Ordering

Ships within 1–2 business days from our warehouse
Free shipping on orders $50 and over
Volume pricing available — save up to 20% when ordering 3 or more kits
Pair it with the UNC kit for a complete Grade 8 imperial fastener inventory
B2B accounts: Custom pricing and a dedicated rep for automotive shops, aerospace facilities, and precision manufacturers — contact us to get started

680 Piece Class 8.8 Cap Screw Assortment Starter Kit

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