US Bolts - Head and Wrench Sizes
Head and wrench size US bolts:
| Bolt Diameter (in) | Head and Wrench Size (in) | |
|---|---|---|
| Hex Bolt Lag Bolt Square Bolt | Heavy Hex Bolt | |
| #6 | 1/4 | |
| #8 | 1/4 | |
| #10 | 5/16 | |
| #12 | 5/16 | |
| 1/4 | 7/16 or 3/8 | |
| 5/16 | 1/2 | |
| 3/8 | 9/16 | |
| 7/16 | 5/8 | |
| 1/2 | 3/4 | 7/8 |
| 9/16 | 13/16 | |
| 5/8 | 15/16 | 1 1/16 |
| 3/4 | 1 1/8 | 1 1/4 |
| 7/8 | 1 5/16 | 1 7/16 |
| 1 | 1 1/2 | 1 5/8 |
| 1 1/8 | 1 11/16 | 1 -3/4 |
| 1 1/4 | 1 7/8 | 2 |
| 1 3/8 | 2 1/16 | |
| 1 1/2 | 2 1/4 | |
- 1 in = 25.4 mm
- ANSI/ASME B18.2.1 Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag Screws (Inch Series)
Related Topics
• Fasteners
Bolts, nuts and threaded rods - torque, tension and loads.
• Miscellaneous
Engineering related topics like Beaufort Wind Scale, CE-marking, drawing standards and more.
Related Documents
Cast Iron Flanges - Stud Reference Chart
The number, diameter and length of studs for cast iron flanges class 125 and 250.
Metric Bolt Heads and Wrench Sizes
ANSI/SO, DIN and JIS bolts.
Metric Steel Bolts - Grades and Property Classes
Metric steel bolts, screws and studs - proof and tensile strength.
Reduced Torque with Lubricated Bolts
Lubrication effect on bolt tension and torque.
Screws - Metric vs. Inches
Metric versus Imperial equivalent screw dimensions.
Steel Bolts - ASTM Grades
ASTM steel bolts - proof and tensile strength.
Steel Bolts - SAE Grades
SAE steel bolts - grades ranging grade 1 to 8.2 - proof and tensile strength.
UNC and UNF - Unified Coarce and Unified Fine Inch Threads
ANSI/ASME B1.1 Unified National Thread - UNC Coarse series and UNF Fine series.
US Bolts - Tensile Strength and Proof Loads
Tensile strength and proof loads SAE bolts.
US Hex Bolts - Inches
ANSI/ASME B18.2.1 Dimensions of Hex Bolts - Imperial units.
US Hex Bolts - Metric
ANSI/ASME B18.2.3M Dimensions of Hex Bolts - Metric units.
US Machine Screws - Dimensions
Machine screw diameters.
Wrench Spanners - Inches vs. mm
Convert between US Inches and metric mm wrench and spanner sizes.