| ICS | Field |
|---|---|
| 21.020 |
Characteristics and design of machines, apparatus, equipment Including reliability, dependability, maintainability, durability, etc. Safety of machinery, see 13.110 |
| 21.040 |
Screw threads Screw threads for aerospace construction, see 49.030.10 |
| 21.060 |
Fasteners Fasteners related to surgery, prosthetics and orthotics, see 11.040.40 Fasteners for aerospace construction, see 49.030 |
| 21.080 | Hinges, eyelets and other articulated joints |
| 21.100 | Bearings |
| 21.120 | Shafts and couplings |
| 21.140 |
Seals, glands Seals for pipe and hose assemblies, see 23.040.80 |
| 21.160 |
Springs Steels for springs, see 77.140.25 |
| 21.180 | Housings, enclosures, other machine parts |
| 21.200 | Gears |
| 21.220 | Flexible drives and transmissions |
| 21.240 |
Rotary-reciprocating mechanisms and their parts Including pistons, piston-rings, crankshafts, etc. for general engineering |
| 21.260 |
Lubrication systems Lubricants, see 75.100 |