Whole-Spec.com
Mechanical Spec Database — KS · ISO · JIS · DIN · ANSI
Engineering reference written by mechanical designers — 20 design practice guides, 12 calculators, 157 AutoLISP routines, and standard part specifications.
187 specs · 1,646 sizes · 5 standards
Spring Finder
Enter outer diameter and required load (kgf) — get auto-recommended compression springs. Iterates 14 standard wire diameters, returning 1–3 candidates that satisfy spring index and stress limits, ranked near 75% stress utilization.
AutoCAD LISP Catalog
157 verified AutoLISP routines, organized by category with instant search. Links lead directly to each author’s official page.
STEP File Library
Free 3D CAD models — 780 files across 17 part families: bolts, nuts, beams, pipes and more. Modeled to real KS/ISO/DIN dimensions, ready for assembly layout and clearance checks.
Design Guide
Bolt Threading Depth - No Such Thing as "Good Enough"
Minimum threading depth by material (Steel 1.5D, Aluminum 2D), effective thread vs drill depth, through-hole vs blind hole design
Tool Clearance - Design for Assembly, Not Just CAD
Socket wrench diameter, spanner swing angle, finger accessibility for assembly-friendly design
Jack Bolt - Design for Disassembly
Jack bolt design for removing interference-fit parts (positioning, quantity, thread protection)
Poka-Yoke - Error-Proof Design, Not Worker Blame
Asymmetric design, physical stops, bolt standardization to eliminate assembly errors
Eyebolt Design - Lifting Points for 15kg+ Parts
Lifting point design for 15kg+ parts, center of gravity calculation, spot facing, thread depth
Chamfer vs Fillet - Cost-Effective Edge Finishing
Exterior chamfer (C), interior fillet (R), stress concentration prevention, cost-saving design
Bearing Fit Selection — Too Loose Means Creep, Too Tight Means Failure
Inner/outer ring fit criteria, rotating vs stationary load, practical selection (JS7/K5)
"The Bolt Just Spins" — Reinforce Aluminum Threads with Helicoil Inserts
Aluminum thread stripping causes, Helicoil and Key-Sert installation, correct tap hole sizing
Machine Seizes When AC Turns Off? How to Design for Thermal Expansion
Thermal expansion coefficients (steel 12×10⁻⁶, aluminum 23×10⁻⁶), calculation formula, sliding joints and long shaft design
"Everything Was in Spec but It Won't Fit" — Tolerance Stackup in Practice
Worst-case vs RSS method comparison, stackup calculation example, design margin strategies
Specifying Ra 0.8 Everywhere Is a Budget Bomb — Surface Roughness in Practice
Machining process and cost by Ra, functional Ra selection guide, drawing callout method
Pneumatic Cylinder Bore Selection — Bigger Is Not Always Better
Thrust calculation (F=P×A×η), safety factor application, speed vs bore relationship, port size selection
Why Welding Warps — Design and Process Strategies to Minimize Distortion
Weld shrinkage direction, pre-distortion, weld sequence, jig and clamp strategies
Three Shaft Design Traps — Steps, Keyways, and Stress Concentration
Step ratio and fillet radius, keyway location and stress concentration, bearing shoulder height, material selection
Wrong O-Ring Groove Dimensions Are Worse Than No Seal — Groove Design in Practice
Compression ratio calculation, dynamic vs static groove dimensions, surface roughness and material selection
Why Does SUS304 Rust? — 5 Corrosion Traps of Stainless Steel
Galvanic corrosion from dissimilar metals, chloride-induced SCC, weld sensitization, crevice corrosion, and passive film breakdown — the real reasons stainless steel corrodes and how to prevent it
7 Sheet Metal Design Rules That Cut Fabrication Cost in Half
Minimum bend radius, hole-to-edge distance (≥2t), bend line to hole spacing, burr direction, flat pattern formulas, tap+bolt vs welding, material utilization — 7 essential sheet metal design rules
Spring Washers Don't Work? — The Truth About Bolt Anti-Loosening
Why spring washers fail in Junker vibration tests, friction vs mechanical locking, and truly effective methods: Nord-Lock, Nyloc, thread adhesive, double nuts, and proper torque management
SS400, S45C, SUS304, A5052 — A Mechanical Designer's Material Selection Decision Tree
Strength→S45C/SCM, corrosion resistance→SUS304/316, lightweight→A5052/A6061, cost→SS400, heat treatment→S45C/SCM, machinability→SUM — material selection decision tree for mechanical designers
You Can't Design Without Knowing Machining — Practical Machining Allowances and Geometric Limits
Milling corner radii (tool R), lathe center holes, grinding allowance (0.2–0.5mm), EDM limits, minimum ID grinding diameter, boring depth limits, undercuts/relief grooves — machining process constraints every designer must know
Fasteners
Power Transmission
Structural
Design Reference
Fits & Tolerances
Fits & Tolerances · 3 types · 14 sizes
Tap/Drill
Tap/Drill · 2 types · 24 sizes
Counterbores
Counterbores · 2 types · 17 sizes
O-Rings
O-Rings · 3 types · 29 sizes
O-Ring Grooves
O-Ring Grooves · 2 types · 9 sizes
Keyways
Keyways · 2 types · 18 sizes
GD&T
GD&T · 4 types · 15 sizes
General Tolerances
General Tolerances · 3 types · 15 sizes
Surface Roughness
Surface Roughness · 2 types · 24 sizes
Surface Treatment
Surface Treatment · 6 types · 21 sizes
Heat Treatment
Heat Treatment · 6 types · 24 sizes
Machining Reference
Machining Reference · 4 types · 71 sizes
Welding Symbols
Welding Symbols · 8 types · 17 sizes
Minimum Bend Radius
Minimum Bend Radius · 9 types · 103 sizes
Why Whole-Spec for English-Speaking Engineers
Whole-Spec consolidates KS, ISO, JIS, DIN, and ANSI/ASME mechanical specifications into a single searchable database, with every dimension table available in both metric and inch units. Engineers working across borders — sourcing ISO bolts for ASME-designed equipment, replacing JIS bearings in a North American facility, or matching DIN keys to legacy machinery — can cross-reference standards without juggling multiple supplier catalogs.
What Sets It Apart
Most fastener databases only cover one standards family. Whole-Spec maps equivalent parts across regions (e.g., ISO 4014 hex bolt ↔ ASME B18.2.1 hex cap screw, JIS B 1180 ↔ DIN 931) and includes recommended Grade 8.8 dry tightening torque tables for immediate shop-floor use. Eleven free calculators (bolt torque, fit tolerance, beam deflection, gear, bearing life, pitch, and more) extend the reference into computational territory — no signup, no paywall.