Such as double-gear 2610-2B is the outer 26 teeth, within 10 teeth, aperture 2mm tight fit

A tight with small 0.05mm aperture than standard
B said loose with than the standard aperture 0.05mm

Calculate the gear diameter:

(Number of teeth +2) * modulus = gear diameter

Gear modulus of the package: 0.5
Aperture: 1.5, 2, 2.5,3

Modulus: 0.5

Aperture 1.5, 2,2.5,3

The mainshaft gears :8-1 .5A 18-2.5A18-3A 82A 10-2A-2A 16-2A 9-2A 12-2A

Crown teeth: C202.5A C24102Ac24102b C30102B
C20-3A C28-2AC30-3A C3610-2B C2810-2A C20-2A

The monolayer Gear: 202A 262A282A402A522.5A 563A24-2.5A 36-2A 38-2A
38-3A 44-2A 44-2.5A 48-2A 46-2.5A 50-3A56-2A 422A 30-2A

Double gear:18102A 48122.5A 4610-2B 4810-2B 2610-2B 2210-2B
3212-2B 2810-2B 3808-2B 2810-2B 3210-2B2808-2B
3412-2B 3610-2B 5010-2B
4410-2B 5610-2A 3010-2B 2410-2B

Worm Gear: 6 * 6 (diameter 6mm * length 6mm), 6 * 8 (a diameter of 6mm, and a length of 8mm)