- Provide exceptional holding strength and withstand high torques – ideal for heavy duty applications.
- Ribbed for rigidity under load.
- Sharp points on periphery resist shifting
- Internal teeth lock into bolt head or nut to prevent backoff.
- Ideal where thick materials and high torques are involved.
| Nominal Washer Size |
Hole Diameter Min. |
Hole Diameter Max. |
Across Flats Min. |
Across Flats Max. |
Across Corners |
Minimum Height | Thickness | WT./M | WCL Part Number |
Cross Reference |
|---|---|---|---|---|---|---|---|---|---|---|
| 1/4 | 0.252 | 0.258 | 0.74 | 0.76 | 0.866 | 0.18 | 0.078 | 8.55 | PYRM-0250-14-01 | 4914-14-01 |
| 5/16 | 0.32 | 0.332 | 0.74 | 0.76 | 0.866 | 0.145 | 0.062 | 6.14 | PYRM-0312-14-01 | 4918-14-01 |
| 5/16 | 0.32 | 0.332 | 0.99 | 1.01 | 1.15 | 0.200 | 0.078 | 13.53 | PYRM-0312-18-01 | 4918-18-01 |
| 3/8 | 0.384 | 0.398 | 0.99 | 1.01 | 1.15 | 0.13 | 0.062 | 12.1 | PYRM-0375-18-01 | 4920-18-01 |
| 3/8 | 0.384 | 0.398 | 1.24 | 1.26 | 1.41 | 0.27 | 0.109 | 36.18 | PYRM-0375-23-01 | 4920-23-01 |
| 7/16 | 0.454 | 0.468 | 1.24 | 1.26 | 1.41 | 0.27 | 0.109 | 34 | PYRM-0437-23-01 | 4922-23-01 |
| 7/16 | 0.446 | 0.45 | 1.355 | 1.375 | 1.576 | 0.195 | 0.093 | 35.71 | PYRM-0437-25-01 | 4922-25-01 |
| 1/2 | 0.512 | 0.529 | 1.24 | 1.26 | 1.41 | 0.195 | 0.109 | 31.95 | PYRM-0500-23-01 | 4924-23-01 |
| 1/2 | 0.512 | 0.529 | 1.355 | 1.375 | 1.576 | 0.21 | 0.093 | 32.26 | PYRM-0500-25-01 | 4924-25-01 |
| 1/2 | 0.512 | 0.529 | 1.355 | 1.375 | 1.576 | 0.19 | 0.093 | 33.06 | PYRM-0500-25-02 | 4924-25-02 |
| 1/2 | 0.512 | 0.529 | 1.355 | 1.375 | 1.576 | 0.24 | 0.093 | 34.00 | PYRM-0500-25-03 | 4924-25-03 |