Metric Hex Bolt Head Dimensions When working with metric fasteners, the wrench size (width across flats) follows a different pattern than US bolts. Here’s the quick reference: Bolt Size Width Across Flats (mm) Width Across Corners (mm) Head Height (mm) M5 8 9.24 3.5 M6 10 11.55 4.0 M8 13 15.01 5.3 M10 16 (or … Read more
The Complete Drill Size Reference Why does this chart exist? Because someone at some point decided that drill bits should come in four completely different naming systems — fractional inches, letter sizes (A–Z), number/gauge sizes (#1–#97), and metric. And engineers need to convert between all of them constantly. This master chart lists all standard drill … Read more
Why You Need This Table Working with international suppliers or drawings from outside the US? The same steel has different names in different countries. This table maps the most common structural and engineering steels across seven national standards. Carbon & Alloy Steel Cross-Reference EN (Europe) SAE/AISI (US) UNS DIN (Germany) BS (UK) UNI (Italy) JIS … Read more
Metric Tap & Clearance Drill Sizes This table covers standard coarse pitch metric threads (the default — if a drawing says “M10” without specifying pitch, it means M10×1.5 coarse). For each thread size, you get the tap drill (for cutting internal threads) and clearance drill (for a bolt to pass through freely). Thread Pitch (mm) … Read more