Spanner Slot Size
ASTM A325 structural bolts are designed for steel to steel connections. Because they are used in such a specific application, they have dimensional characteristics that are unique and limited compared to most other fastener grades. This includes stock sizes available in the market place, length tolerances, short thread lengths, and the actual head dimensions are the same as any heavy hex head bolt (Dimensions per ASME B18.2.6 2011).
The Spanner size selection is enabled by the use of an accessory, The Surveyor™ urethral measurement device. The Surveyor is designed to assess the length of the urethra from the bladder neck to the bottom side of the external sphincter in order to select the appropriate Spanner size. This revision has been taken up to align the dimensions. Sizes 2, 2.5, 3, 3.5, 4.5, and above 210 are not appearing in IS0 691-1983. The details of these sizes are in accordance with DIN 475 ( Part 2 )-I976 ‘Widths of opening of spanners’ issued by Deutsches lnstitut fiir Normung (DIN).
Available Sizes
This table is the chart for publication of information of wrench sizes in inches (US) and millimeters (metric), as well as British spanner size information. The slots on an M-Lok handguard are approximately 32 mm (1.260 in) long and 7 mm (0.276 in) wide and space 8 mm (0.315 in) from each other. The radius of the corners is.
Although technically any size A325 can be custom manufactured, there are certain restrictions as well as common lengths which are more readily available in the marketplace. Depending on the diameter, there may be longer lengths available.
| Diameters Allowed: | 1/2″ – 1-1/2″ |
|---|---|
| Available Lengths: | Up to 6″ – 10″ maximum (depending on diameter) |
| Available Finish: | Plain Finish or Hot Dip Galvanized |
| Origin: | Import or Domestic |
Bolt Length Tolerances
Spanner Nut Socket Sizes
| Nominal Length, in. | Nominal Size, in. | |||
|---|---|---|---|---|
| 1⁄2 | 5⁄8 | 3⁄4 thru 1 | 11⁄8 thru 11⁄2 | |
| Thru 6 in. | -0.12 | -0.12 | -0.19 | -0.25 |
| Over 6 in. | -0.19 | -0.25 | -0.25 | -0.25 |
Structural Bolt Dimensions
Although the head dimensions for structural bolts are the same as any heavy hex headed fastener per ASME B18.2.6 2011, A325 heavy hex bolts have a shorter thread length than most other construction fastener grades.
Adjustable Spanner Sizes
| Bolt Diameter | D | F | C | H | T | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Body Diameter | Width Across Flats | Width Across Corners | Height | Thread Length | ||||||
| Max | Basic | Max | Min | Max | Min | Basic | Max | Min | Basic | |
| 1⁄2 | 0.515 | 7⁄8 | 0.875 | 0.850 | 1.010 | 0.969 | 5⁄16 | 0.323 | 0.302 | 1.00 |
| 5⁄8 | 0.642 | 11⁄16 | 1.062 | 1.031 | 1.227 | 1.175 | 25⁄64 | 0.403 | 0.378 | 1.25 |
| 3⁄4 | 0.768 | 11⁄4 | 1.250 | 1.212 | 1.443 | 1.383 | 15⁄32 | 0.483 | 0.455 | 1.38 |
| 7⁄8 | 0.895 | 17⁄16 | 1.438 | 1.394 | 1.660 | 1.589 | 35⁄64 | 0.563 | 0.531 | 1.50 |
| 1 | 1.022 | 15⁄8 | 1.625 | 1.575 | 1.876 | 1.796 | 39⁄64 | 0.627 | 0.591 | 1.75 |
| 11⁄8 | 1.149 | 113⁄16 | 1.812 | 1.756 | 2.093 | 2.002 | 11⁄16 | 0.718 | 0.658 | 2.00 |
| 11⁄4 | 1.277 | 2 | 2.00 | 1.938 | 2.309 | 2.209 | 25⁄32 | 0.813 | 0.749 | 2.00 |
| 13⁄8 | 1.404 | 23⁄16 | 2.188 | 2.119 | 2.526 | 2.416 | 27⁄32 | 0.878 | 0.810 | 2.25 |
| 11⁄2 | 1.531 | 23⁄8 | 2.375 | 2.300 | 2.742 | 2.622 | 15⁄16 | 0.974 | 0.902 | 2.25 |
Dimensions per ASME B18.2.6 2011 | ||||||||||