Standard DP spur gears
Inch-system straight-tooth gears produced to the confirmed diametral pitch, pressure angle, and mounting drawing.
custom inch gears
Inch and DP Gears
Custom diametral-pitch spur gears and replacement components for inch-based machinery.
Product overview
Technical overview of custom inch gears.
Custom inch gears use diametral pitch and inch-based dimensions rather than metric module. They remain important for replacement machinery, imported equipment, legacy reducers, and assemblies designed around Imperial standards. ZhongYi reviews inch gear enquiries from drawings or samples, including diametral pitch, pressure angle, tooth count, pitch diameter, face width, bore, hub, keyway, material, heat treatment, tolerance, and the mating gear. A DP gear should not be substituted with a visually similar module gear because pitch and tooth geometry must match the existing center distance and mating component.
Product types
Inch and DP Gears types and manufacturing paths.
The final product form is confirmed from the buyer drawing, mating component, assembly layout, operating conditions, and inspection requirements.
Hardened or ground inch gears
Replacement or OEM components where the technical file defines heat treatment and post-treatment tooth finishing.
Finished-bore and hub designs
Gears supplied with drawing-defined bores, keyways, splines, set-screw features, hubs, and datum faces.
Sample-based replacement gears
Legacy parts reviewed with the mating gear, center distance, shaft, housing, material, and operating conditions.
Selection guidance
How to specify the correct configuration.
Identify diametral pitch and pressure angle before measuring only the outside diameter. A worn sample can make tooth thickness difficult to recover, so provide center distance, mating gear tooth count, shaft dimensions, and any machine manual or drawing. Confirm whether dimensions are fractional, decimal-inch, or mixed with metric features. Material, heat treatment, bore, keyway, hub, backlash, speed, load, and lubrication should be documented. If the machine has been repaired previously, verify that the sample is the intended design rather than an earlier workaround.
Material Options
- Carbon steel for general replacement gearing
- Alloy steel for specified heat treatment or wear duty
- Stainless steel for selected corrosion-conscious systems
- Engineering materials when defined by the approved drawing
Selection Factors
- Diametral pitch, pressure angle, and tooth count
- Pitch diameter, center distance, and mating gear
- Bore, keyway, spline, hub, face width, and inch tolerances
- Material, heat treatment, hardness, and tooth finishing
- Load, speed, duty cycle, lubrication, and replacement history
Applications
Inch and DP Gears application fit.
Match the gear type with real machinery conditions, operating environment, load, speed, and replacement requirements.
- Legacy industrial machinery and reducers
- Imported equipment with inch-based gear geometry
- Maintenance replacement and reverse-review projects
- OEM products designed around diametral pitch
Quality and technical verification
Inspection requirements tied to approved technical data.
Useful engineering evidence is more valuable than unsupported quality claims. Critical checks, records, and acceptance criteria are defined from the drawing and purchase requirement.
Inch gear procurement benefits from disciplined unit control. ZhongYi can review the drawing unit system, DP, pressure angle, tooth count, blank geometry, bore and keyway, material, heat treatment, and inspection notes before quotation. Inspection requirements may include inch-based dimensions, runout, tooth thickness, pitch-related checks, hardness, and mating fit when specified. Metric conversions used for internal planning should not replace the buyer-approved inch drawing. Critical geometry, accuracy grade, and documentation remain subject to technical confirmation.
All products can be custom manufactured from drawings or samples.
Buyer FAQ
Common technical and purchasing questions.
These answers support early technical review. Final dimensions, materials, tolerances, and process requirements are confirmed against the approved file for each enquiry.
What is the difference between module and diametral pitch?
Module describes metric tooth size, while diametral pitch expresses the number of teeth per inch of pitch diameter. They are related mathematically but should not be interchanged without recalculating the complete gear geometry.
Can an inch gear be copied from a worn sample?
A sample can support review, but the original pressure angle, tooth thickness, and heat treatment may be uncertain. The mating gear, center distance, shaft dimensions, machine documentation, and operating conditions improve confidence.
Which units should be used on the drawing?
Use one clear primary unit system and identify any exceptions. Keep diametral pitch and critical inch dimensions explicit, and avoid rounded metric conversions that could change fit or gear mesh.
Custom manufacturing
Send drawings or samples for technical review.
ZhongYi can review geometry, material, heat treatment, bore, keyway, tooth profile, application conditions, and order quantity before quoting.
Related product categories
Request a quote
Send drawings, samples, or technical requirements for review.
Our team can review your gear type, material, heat treatment, tolerance, order quantity, and application conditions before quotation.