Cylindrical gear module 4 Z-15 straight toothed in steel

Dear customer,

Thank you for your inquiry.

For a spur gear module 4 with 15 teeth (Z15) and an outside diameter (OD) of 68 mm, the standard center distance with a mating rack gear of the same module is calculated as follows:

• Working depth (total depth of engagement):
  ≈ 2.25 × module = 9 mm

• Standard backlash (clearance) between gear and rack:
  Typically 0.05 mm to 0.20 mm depending on the application (light, medium, or heavy load, speed, and precision required).

This clearance ensures smooth operation and prevents binding due to thermal expansion, deflection, or minor alignment errors.

If you're using a standard straight rack gear (module 4), the recommended center height between the gear pitch circle and rack pitch line is exactly 30 mm (module × Z / 2), and the addendum clearance (gap between tooth tip of the gear and bottom of the rack tooth space) should be around 0.25 mm.

Let us know if you need a compatible rack gear – we can only offer the products currently available on our website.

All our products are intended for professional use and must be installed by qualified personnel.
Please verify compatibility with your application before ordering.

Best regards,
Adajusa