Specifications For Set Screws
| Raw Materials -Set screws shall be made of steel conforming to the requirements specified below. -For property class 45H, other materials may be used provided that the torque test requirements are met. |
| Property Class | Material | Heat Treatment | Chemical Composition % | |||
|---|---|---|---|---|---|---|
| C | P max. | S max. | ||||
| max. | min. | |||||
| 14H | Carbon Steel1)2) | - | 0.50 | - | 0.11 | 0.15 |
| 22H | Carbon Steel3) | Quenched and Tempered | 0.50 | - | 0.05 | 0.05 |
| 33H | Carbon Steel3) | Quenched and Tempered | 0.50 | - | 0.05 | 0.05 |
| 45H | Carbon Steel3)4) | Quenched and Tempered | 0.50 | 0.19 | 0.05 | 0.05 |
| 1)Free-cutting steel may be used, with lead content 0.35% max., phosphorus content 0.11% max., and sulphur content 0.34% max. 2)Case hardening is allowed in the case of square-head set screws. 3)Steel with lead content 0.35% max. may be used. 4)Shall contain one or more of alloying elements chromium, nickel, molybdenum, vanadium or boron. |
Mechanical Properties
| Property Class | ||||||
|---|---|---|---|---|---|---|
| 14H | 22H | 33H | 45H | |||
| Vickers Hardness HV | min. | 140 | 220 | 330 | 450 | |
| max. | 290 | 300 | 440 | 560 | ||
| Brinell Hardness HB, F=30 D2 | min. | 133 | 209 | 314 | 428 | |
| max. | 276 | 285 | 418 | 532 | ||
| Rockwell Hardness | HRB | min. | 75 | 95 | - | - |
| max. | 105 | - | - | - | ||
| HRC | min. | - | - | 33 | 45 | |
| max. | - | 30 | 44 | 53 | ||
| Minimum Height Of Non-decarburized thread zone, E | - | 1/2H1 | 2/3H1 | 3/4H1 | ||
| Maximum depth of complete decarburization, G (mm) | - | 0.015 | 0.015 | ** | ||
| Surface Hardness HV 0.3 (max) | - | 320 | 450 | 580 | ||
| Pitch of the thread | P mm | 0.5 | 0.6 | 0.7 | 0.8 | 1 | 1.25 | 1.5 | 1.75 | 2 | 2.5 | 3 | 3.5 | 4 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| H1 | mm | 0.307 | 0.368 | 0.429 | 0.491 | 0.613 | 0.767 | 0.920 | 1.074 | 1.227 | 1.534 | 1.40 | 2.147 | 2.454 | |
| E min mm | Property Class | 22H | 0.154 | 0.184 | 0.215 | 0.245 | 0.307 | 0.384 | 0.460 | 0.537 | 0.614 | 0.767 | 0.920 | 1.074 | 1.227 |
| 33H | 0.205 | 0.245 | 0.286 | 0.327 | 0.409 | 0.511 | 0.613 | 0.716 | 0.818 | 1.023 | 1.227 | 1.431 | 1.636 | ||
| 45H | 0.230 | 0.276 | 0.322 | 0.368 | 0.460 | 0.575 | 0.690 | 0.806 | 0.920 | 1.151 | 1.380 | 1.610 | 1.841 | ||
Torque Requirements
| Nominal Thread Diameter | Minimum Length Of Screw For Test (mm) | Test Torque N x m | |||
|---|---|---|---|---|---|
| Flat Point | Cup Point | Cone Point | Dog Point | ||
| 3 | 4 | 4 | 5 | 5 | 0.9 |
| 4 | 5 | 5 | 6 | 6 | 2.5 |
| 5 | 5 | 6 | 8 | 8 | 5 |
| 6 | 8 | 8 | 8 | 8 | 8.5 |
| 8 | 8 | 10 | 10 | 10 | 20 |
| 10 | 10 | 12 | 12 | 12 | 40 |
| 12 | 16 | 16 | 16 | 16 | 65 |
| 16 | 20 | 20 | 20 | 20 | 160 |
| 20 | 20 | 25 | 25 | 25 | 310 |
| 24 | 25 | 30 | 30 | 30 | 520 |
*All information is strictly informative