WhatSizeBolt Knowledge Hub — Fastener Guides & How-Tos
In-depth guides on bolt sizes, torque specs, fastener grades, thread pitch, and shop repair tips. Browse the knowledge hub for plain-English explanations of how fasteners work and how to choose, measure, and torque them correctly.
Fastener fundamentals
Start with the basics: how bolt sizing works in metric and SAE, how to read grade markings, and how thread pitch affects fit and clamp load. These guides give you the vocabulary to identify any fastener and pick the right replacement.
Torque and repair guides
Learn why torque-to-yield bolts must never be reused, how dry versus lubricated torque changes the spec, and the correct tightening sequence for wheels and cylinder heads. Check the scope and source notes in each guide; source links do not establish completed technical review.
Featured guides & tools
Torque specs (21)
Head bolts, lug nuts, drain plugs, torque charts and the procedure behind them.
- F-150 Rear Differential Fluid Change: Ford 8.8 & 9.75 Drain, Fill, Sealant and Cover Torque
- Torque Wrench Extensions & Crowfoot Adapters: When Your Setting Changes (With Calculator Math)
- Brake Caliper Bolts Explained: Guide Pins, Bracket Bolts and the Bleeder Screw
- 2024 Silverado 5.3L L84 Head Bolt Torque & Sequence (and Intake Manifold)
- Torque Wrench Sizes: When You Need an Inch-Pound Wrench (and Why Range Matters)
- Drain-Plug Washers, O-Rings and Washerless Designs: What Actually Seals?
- Differential Cover Bolt Torque: Dana 30, 35, 44 & 60
- Ford 4.6 & 5.4 Modular V8 Head Bolt Torque & Sequence (2V, 3V, 4V)
- Ford 302 / 5.0 Windsor Head Bolt Torque & Tightening Sequence (1968-2001)
- 5.7 HEMI Head Bolt Torque & Tightening Sequence (2003-Present, Gen III)
- Lubricated vs Dry Bolt Torque: The K-Factor Chart (and How Much to Cut the Spec)
- Stainless Steel Bolt Torque Chart: A2-70 & A4-80 (M3–M24)
- A Bolt Is a Spring: Clamp Force, Stretch and Why Engine Builders Measure Instead of Torque
- How to Use a Torque Wrench: Click, Beam & Digital (the Right Way)
- GM 3800 V6 Head Bolt Torque & Tightening Sequence (Series II & III)
- LS Head Bolt Torque & Tightening Sequence (Gen III & Gen IV)
- Chevy 350 Small-Block Head Bolt Torque & Tightening Sequence
- Wheel Torque Specs: The Complete Lug Nut Torque Guide
- Summer Road Trip Car Checklist: Torque Specs That Keep You Safe
- Oil Drain Plug Sizes by Vehicle Make - Complete Guide
- Torque Specifications: Why They Matter and How to Use Them
Identify & measure (14)
Sizes, thread pitch, standards and head markings — what you are holding and what replaces it.
- Tap Drill Size Chart: Metric (M2-M30) & UNC/UNF (#4-1") with the Formula Behind It
- BSP & BSPT Pipe Thread Size Chart
- The Hidden Math in Your Bolt Bin
- How to Identify a Hydraulic Fitting: JIC, ORFS, ORB and NPT
- 100 Years of Socket Drives: Why the 3/8" Drive Won the Garage
- Phillips vs. Pozidriv vs. JIS: The Three Incompatible Screw Drives
- Whitworth Spanner & Socket Size Chart: BSW & BSF Across-Flats to Metric
- Why 10mm and 3/8" Dominate Automotive Fasteners: The Engineering History
- British Thread Standards Explained: BSW, BSF, BA, BSP & BSC
- Bolt Pattern (PCD) Explained: How to Read & Measure It
- Coarse vs Fine Thread: Which Is Stronger? (And When to Use Each)
- Metric vs Standard Bolts: Key Differences Explained
- How to Measure a Bolt: Length, Diameter & Thread Pitch
- Bolt Grades & Material Markings
Repair & removal (7)
Stripped, seized, broken and cross-threaded fasteners, and the holes they leave behind.
- How to Drill and Tap a Broken Bolt: The Thread Repair Guide (Drill, Tap, Insert)
- How to Fix Cross-Threaded Bolts and Nuts: A Step-by-Step Guide
- Best Tools for Removing Rusted Bolts: A Mechanic's Complete Toolkit
- Stripped Spark Plug Thread Repair: Helicoil vs. TimeSert vs. Rethreader
- How to Drill Out a Broken Bolt (Step-by-Step Guide)
- How to Fix a Stripped Screw Hole in Wood (5 Proven Methods)
- Common Fastener Problems and How to Fix Them
Materials & chemicals (8)
Grades, coatings, anti-seize, threadlocker, and when a bolt can be reused.
- Fastener Material Selection Guide
- When to Replace vs. Reuse Bolts: A Mechanic's Decision Guide
- The Complete Guide to Bolt Grades, Heat Treatment, and Hydrogen Embrittlement
- Copper vs. Nickel Anti-Seize: Which Compound Should You Use?
- Lock Washers: Do They Actually Work? (And What to Use Instead)
- Oil vs Anti-Seize on Bolts: When to Use Each (and When NOT To)
- Blue vs Red Threadlocker: Complete Guide (Colors, Brands & Codes)
- Fastener Safety: Critical Guidelines for Safe Installation
Tools & picks (3)
Sockets, wrenches, kits and gift picks that earn their drawer space.
DIY diagnostics (6)
OBD2 and multimeter checks you can run in the driveway.
Australia (Nm) (6)
Wheel nut torque in newton-metres for the utes and SUVs Australia actually drives.
Small engine torque guides
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