Standard Flat Washer Sizes Flat washers distribute load under a bolt head or nut, protect the surface from damage, and span oversized or slotted holes. The two common types in the US are: Type A (Narrow) — general purpose, standard series Type B (Wide) — larger OD for better load distribution on soft materials Dimensions … Read more
Standard Hex Nut Sizes These are the basic dimensions for standard hex nuts per ASME B18.2.2. The “width across flats” is what you need for wrench/socket sizing. Nominal Size Threads/in (UNC) Width Across Flats (in) Width Across Corners (in) Height (in) 1/4″ 20 7/16 0.505 7/32 5/16″ 18 1/2 0.577 17/64 3/8″ 16 9/16 0.650 … Read more
Standard Hex Cap Screw Dimensions Hex cap screws (also called hex cap bolts or hex head bolts) are the workhorse fastener of mechanical assembly. This table covers dimensions per ASME B18.2.1 — the data you need for designing bolt holes, counterbores, clearances, and grip lengths. Key Dimensions Explained Width across flats (F) — your wrench/socket … Read more
400 Series — Cross-Section: 0.275″ This table lists all standard o-ring sizes in the AS568 400 series (dash numbers 350–439). All o-rings in this series have a cross-section diameter of 0.275″. The inner diameter (ID) ranges from 0.176″–26.940″. Need help designing a groove for these o-rings? See the Static O-Ring Groove Design Guide. For other … Read more
300 Series — Cross-Section: 0.210″ This table lists all standard o-ring sizes in the AS568 300 series (dash numbers 265–349). All o-rings in this series have a cross-section diameter of 0.210″. The inner diameter (ID) ranges from 4.975″–22.940″. Need help designing a groove for these o-rings? See the Static O-Ring Groove Design Guide. For other … Read more
200 Series — Cross-Section: 0.139″ This table lists all standard o-ring sizes in the AS568 200 series (dash numbers 201–264). All o-rings in this series have a cross-section diameter of 0.139″. The inner diameter (ID) ranges from 0.171″–16.955″. Need help designing a groove for these o-rings? See the Static O-Ring Groove Design Guide. For other … Read more
100 Series — Cross-Section: 0.103″ This table lists all standard o-ring sizes in the AS568 100 series (dash numbers 115–178). All o-rings in this series have a cross-section diameter of 0.103″. The inner diameter (ID) ranges from 0.487″–11.196″. Need help designing a groove for these o-rings? See the Static O-Ring Groove Design Guide. For other … Read more
000 Series — Cross-Section: 0.070″ This table lists all standard o-ring sizes in the AS568 000 series (dash numbers 001–114). All o-rings in this series have a cross-section diameter of 0.070″. The inner diameter (ID) ranges from 0.029″–5.234″. Need help designing a groove for these o-rings? See the Static O-Ring Groove Design Guide. For other … 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
UNF Tap Drill Sizes UNF (Unified National Fine) threads have more threads per inch than UNC for the same diameter. They’re stronger in thin-walled parts, provide finer adjustment, and resist vibration loosening better — but they’re less forgiving and easier to cross-thread. Thread Size TPI Tap Drill Decimal (in) 75% Thread Clearance Drill #0-80 80 … Read more