O-Ring Supply Co.
ISO Certified
10,000+ O-Ring Sizes
Custom Manufacturing

Custom Sealing Parts and O-Ring Manufacturing

From custom O-rings to drawing-based sealing parts, we support prototype to production with fast engineering feedback, MOQ from 1 piece, and no mold fees for standard circular profiles.

Overview

Not every sealing application fits a standard size chart. We support both custom O-rings and drawing-based sealing parts manufactured to your exact dimensional, material, hardness, and color requirements. Because we operate an in-house mold shop, we can move from your drawing or sample to a cured part in days, not weeks.

This service is designed for OEM buyers, maintenance teams, and engineers who need more than an off-the-shelf size. If the requirement is non-standard, under development, or tied to a specific groove or assembly condition, we can review it and recommend the most practical manufacturing approach.

What We Can Customize

Custom Dimensions

Any ID and CS combination. We manufacture from micro-size O-rings up to large-diameter flange seals.

Material Selection

NBR, FKM, EPDM, VMQ (Silicone), PTFE, and specialty compounds including FDA, USP Class VI, NSF 61, and low-temp grades.

Hardness and Color

Standard hardness from 40 to 90 Shore A. Custom colors available for material identification and branding.

Special Profiles

Square-cut rings, X-rings, backup rings, and custom cross-sections for unique groove geometries.

Drawing-Based Parts

Send a 2D drawing, 3D model, or marked-up sample photo for non-standard sealing parts, OEM replacements, and development-stage components.

Prototype and Small-Batch Runs

Ideal for validation builds, pilot runs, maintenance spares, and urgent replacements before full production quantities are released.

Typical Project Types

Custom O-Rings

Non-standard inside diameters, cross-sections, special tolerances, and low-volume prototypes for new projects or difficult replacements.

Special Sealing Profiles

Square rings, X-rings, backup rings, and other profile changes needed to match groove geometry, pressure conditions, or installation constraints.

OEM and Replacement Parts

Drawing-based parts for existing equipment, discontinued sizes, imported machinery, and private-label replacement programs.

Large-Diameter and Low-Volume Jobs

Practical support for flange seals, pressure vessel rings, and oversized parts where standard stock is not available.

How to Order Custom Parts

Step 1

Submit Drawing or Sample

Send us a CAD drawing, dimensional sketch, or physical sample. Include material, hardness, quantity, and application details.

Step 2

Engineering Review

Our engineers review your specifications for manufacturability and recommend the most efficient molding approach.

Step 3

Tooling and Sampling

For standard circular profiles, no mold fee applies. Custom profiles are tooled in-house. First-article samples ship in 3-5 days.

Step 4

Approval and Production

Once samples are approved, we schedule production. Standard lead time is 7-15 days.

No Mold Fee Policy

For any O-ring with a standard circular cross-section, we do not charge a mold fee even for custom inner diameters. This is possible because our in-house mold shop can machine cavity plates quickly and cost-effectively. Mold fees apply only to complex non-standard profiles that require unique tooling geometry.

What to Send With Your RFQ

  • Part drawing, sketch, or clear dimensions
  • Material requirement or service media
  • Operating temperature, pressure, and motion type
  • Quantity, target lead time, and sample requirement
  • Photos or sample notes for replacement parts

Frequently Asked Questions

Do you charge mold fees for custom sizes?

No mold fees apply to standard circular cross-section profiles with custom inner diameters. Mold fees apply only to special profiles, custom shapes, or tooling that requires a unique cavity geometry.

What is the minimum order quantity for custom parts?

MOQ starts at 1 piece. We accept prototype quantities for validation before you commit to larger production runs.

How do I send you a drawing?

Email your drawing to yaoqingpu1983@gmail.com or upload the details through the quote request form. We accept PDF, DWG, DXF, STEP, and common image formats.

Can you match a competitor's material specification?

Yes. If you provide the compound specification or ASTM D2000 callout, we can match or exceed the required properties.

Do you provide samples before full production?

Yes. We strongly recommend first-article samples for new custom sizes and development-stage parts. Sample lead time is typically 3-5 days.

Do you only make custom O-rings?

No. We supply both standard catalog sizes and custom-made parts. This page focuses on custom work, but many customers order standard and custom sealing parts together in the same project.

Can you review OEM replacement parts from a sample or photo?

Yes. If a drawing is not available, send a physical sample or clear photos with critical dimensions. We can usually evaluate feasibility and suggest the best way to reproduce the part.

Ready to Start Your Custom Order?

Send us your drawing, sample, or standard size requirement for a fast technical quote and manufacturing review.