When a standard catalog part does not fit, a custom machined part can be produced from an engineering drawing, a 3D model or a physical sample. This guide lists the part types, processes and materials involved and explains what to send for a fast, accurate quotation.

Typical Custom Parts and Processes

Available materials include steel, stainless steel, aluminum, brass and engineering plastics. A drawing is required for production. See the custom machined parts range.

Drawing Checklist

• All dimensions with tolerances, and the unit (mm or inch)
• Material grade and the standard it refers to
• Heat treatment and hardness, with the area where it applies
• Surface finish and any coating or plating
• Thread specifications and geometric tolerances
• Critical dimensions marked for inspection
• Drawing revision, quantity and expected annual volume

Custom Parts That Work with Standard Components

Many custom parts connect to catalog items: a gear shaft that carries a spur gear, a shaft end machined for a ball screw support unit or a hub for a taper bushing. Sending the drawing of the mating standard part helps confirm fits and keyway sizes.

Drawing-Based Production

A complete engineering drawing is the preferred basis for quotation and production. It should define dimensions, tolerances, material, heat treatment, surface finish, thread specifications, geometric requirements and any critical inspection points.

Where only a three-dimensional model is available, a two-dimensional drawing is still useful for communicating tolerances, surface requirements and notes that may not be contained in the model.

Using Physical Samples

A physical sample can help identify geometry and interfaces, but it may contain wear, deformation or previous repair work. The customer should confirm whether the part must match the worn sample or the intended original dimensions.

Material grade and heat treatment cannot always be determined accurately from appearance alone. When these properties are unknown, they should be discussed before production.

Typical Component Types

The custom machining overview includes shafts, gears, sprockets, pulleys, hubs, flanges, mounting blocks and other turned or milled components used in transmission and automation equipment.

The manufacturing route may involve CNC turning, milling, gear cutting, drilling, grinding, heat treatment, surface treatment and dimensional inspection depending on the drawing.

Quotation Information

Customers should provide the drawing revision, quantity, material, required delivery schedule, annual usage estimate and any documentation requirements.

Clearly identifying critical dimensions and functional surfaces helps focus the technical review and inspection plan.

Confidential Technical Review

TJOND can review drawings and samples for manufacturability before quotation. Any unclear or conflicting requirement should be resolved before production rather than assumed.

Design for Manufacturability

Small changes to a drawing can sometimes reduce machining time or inspection difficulty without changing function. Examples include using a standard thread, increasing an internal corner radius, avoiding unnecessary deep pockets or applying tight tolerances only to critical surfaces.

Any proposed change must be approved by the customer before production. The purpose of a manufacturability review is to identify options and risks, not to alter the design without authorization.

Prototype and Production Orders

Prototype quantities may use a different process from repeat production. Setup, tooling and programming costs are distributed over fewer parts, so the prototype unit price may be higher. Customers should provide both initial quantity and expected future demand where available.

After a prototype is approved, the drawing revision and inspection requirements should be frozen before larger production orders are placed.

Information Customers Can Prepare

Before sending files, customers should confirm that the drawing revision is current and that all referenced standards are available. A separate note can identify dimensions that are critical to assembly or performance.

When confidentiality requirements apply, they should be communicated before drawings are exchanged. Quotation timing depends on drawing completeness, process complexity, quantity and required documentation.

Frequently Asked Questions

Can you make a part from a sample without a drawing?

A sample can be measured to create a drawing, which should then be approved before production. Wear on the sample and unknown heat treatment need to be discussed first.

Is a 3D model enough?

A 3D model defines geometry, but a 2D drawing is still recommended to state tolerances, surface finish, material and heat treatment.

Why is a prototype more expensive per piece?

Setup, programming and fixtures are shared over fewer parts. Send the expected production volume with the prototype request so both can be quoted.

Related Products

• Custom machined parts
• Spur gears
• Ball screws
• Taper bushings

Have a drawing, a model number or only a worn sample? Send it with the operating conditions for a technical review and quotation.