Being a high speed, high material removal application with stringent demands on the thread profile, generating threads on taps and drills by grinding isn't an easy job.
CUMI's Thread grinding wheels are formulated with high purity, Sharp Aluminium Oxide grains combined with a special glassy, fusible bond. This ensures excellent form retention of the wheel, which translates into consistent thread profile of components.
| Abrasive used | CUMI Code | Grit | Diameter ( mm ) | Diameter ( Inch ) | Thickness ( mm ) | Thickness ( Inch ) | Speed (mps) | Hardness | Structure |
|---|---|---|---|---|---|---|---|---|---|
| Sharp Aluminium Oxide | 55A | 120 - 220 | 200 - 510 | 8 - 20 | 6 - 40 | 1/4 to 1 1/2 | upto 80 | I - M | 4 - 10 |
| White Aluminium Oxide | AA | 120 - 400 | |||||||
| Pink Aluminium Oxide | RA | Upto 150 |
| Thread (pitch, mm) | Best | Better | Good |
|---|---|---|---|
| 0.4—0.7 | - | - | AA400 K9 VF920/80 |
| 0.8—1.0 | - | 55A320 K9 VF920/80 | AA320 K9 VF920/80 |
| 1.25 — 1.5 | - | - | AA280 L10 V457/80 |
| 1.75 —2.0 | - | 55A220 J9 V457/80 | AA240 L9 V457/80 |
| 2.25 | 1CUMISA220 K9 V457/80 | 55A220 K9 V457/80 | AA220 M9 V457/80 |
| 2.50 - 3.00 | 1CUMISA180 L9 V457/80 | 55A180 K9 V457/80 | AA180 M9 V457/80 |
| 3.25 -4.00 | 1CUMISA150 L9 V457/80 | 55A150 L8 V457/80 | AA150 M9 V457/80 |
| Thread (pitch,MM) | TPI | Grading |
|---|---|---|
| 0.7 | 36 | GC400 I5 VMG |
| 0.8 | 32 | |
| 1 | 25 | GC320 I5 VMG |
| 1.25 | 50 | |
| 1.5 | 17 | GC280 I5 VMG |
| 1.75 | 15 | |
| 2 | 13 | GC220 I5 VMG |
| 2.5 | 10 | |
| 3.5 | 7 | |
| 4 | 6 |
Bonded Thread Grinding Catalogue
