✓ ISO 9001:2015 Certified | ✓ Tolerances to 0.0001″ | ✓ Diameters 0.038″ – 1.500″ | ✓ Polish & Regular Finish | ✓ Tungsten Carbide Specialists | ✓ Customer-Supplied Material Accepted

Extramet Products provides precision centerless grinding services specializing in tungsten carbide rods, blanks, and round-stock components. With a diameter range of 0.038″ – 1.500″ (1.25 mm–32.6 mm) and tolerances as tight as 0.0001″, our centerless grinding capability is purpose-built for the exacting demands of aerospace, medical, oil & gas, automotive, and industrial applications. We grind both our own stock carbide material and customer-supplied material — delivering consistent OD precision, superior surface finish, and fast turnaround under our ISO 9001:2015 quality system.

0.0001″
Tightest Tolerance
0.038″ – 1.500″
Diameter Range
Polish & Regular
Finish Options
ISO 9001:2015
Certified Quality
Since 1998
US Operations

Centerless Grinding Capabilities

The table below summarizes Extramet’s verified centerless grinding specifications. All values apply to tungsten carbide unless otherwise noted.

Specification Extramet Capability Notes
Diameter Range 0.038″ – 1.500″ Published standard stock range
Tolerance As tight as ±0.0001″ Diameter tolerance on finished OD
Surface Finish Polish finish & regular finish Specify at time of quote
Primary Material Tungsten carbide (all grades) Customer-supplied material accepted
Quality Standard ISO 9001:2015 All grinding operations covered
Material Source Extramet stock or customer-supplied Both accepted

Contact us with your diameter, tolerance, finish, and quantity requirements for a fast, accurate quote.

What Is Centerless Grinding?

Centerless grinding is a machining process that removes material from the outside diameter of a workpiece using two rotating wheels — a grinding wheel and a regulating wheel — without the need for a spindle, chuck, or center point. The workpiece rests on a work-rest blade positioned between the two wheels. The grinding wheel removes material while the regulating wheel controls the rotational speed and axial feed of the part.

Because no fixturing is required, centerless grinding is exceptionally fast, repeatable, and well-suited for high-volume production of cylindrical components. The absence of centers also eliminates the risk of axial thrust on the workpiece, making the process ideal for hard, brittle materials such as tungsten carbide where end pressure could cause cracking or chipping.

Centerless Grinding Process Types

There are three primary methods of centerless grinding. Understanding which method applies to your component is important when requesting a quote.

Through-Feed (Thru-Feed) Grinding
The workpiece is fed axially through the machine in a continuous pass. Ideal for simple cylindrical parts such as rods and bars consistent in diameter along their full length. The preferred method for high-volume production runs.
In-Feed (Plunge) Grinding
The workpiece is held stationary axially while the grinding wheel feeds radially into the part. Used for components with complex profiles, multiple diameters, shoulders, or tapers that cannot be fed through the machine.
End-Feed Grinding
A variation of in-feed grinding where the workpiece is fed axially to a fixed stop. Used for tapered components where the taper must be ground to a precise end-point. The wheel is dressed to the required taper profile.
⚠ Note: Speak with Extramet today to see which of the above methods are currently available for your specific application. Contact us for details.

Precision Centerless Grinding for Tungsten Carbide

Tungsten carbide is one of the hardest engineering materials in commercial use — with a hardness of 85–95 HRA and a compressive strength exceeding 600,000 psi. These properties make it exceptionally resistant to wear, deformation, and corrosion, but they also make it extremely challenging to grind. Conventional abrasive wheels are ineffective; diamond or CBN wheels, precise coolant management, and controlled infeed rates are required to achieve the tolerances and surface finishes that carbide applications demand.

Extramet’s centerless grinding operation is built specifically around tungsten carbide. Our process parameters, wheel specifications, and quality controls are optimized for carbide — not adapted from a general-purpose grinding program. This specialization means we consistently hold tolerances to 0.0001″ and deliver surface finishes appropriate for tooling, medical, and precision industrial applications.

We grind all Extramet carbide grades as well as customer-supplied material. If you are unsure which grade is appropriate for your application, our team can assist with grade selection before grinding begins.
Property Typical Value
Hardness 85–95 HRA
Compressive Strength >600,000 psi
Density 14.0–15.0 g/cm³
Modulus of Elasticity ~80,000,000 psi
Grinding Wheel Diamond or CBN

Advantages of Centerless Grinding

Centerless grinding offers several performance and production advantages over other OD grinding methods, particularly for cylindrical components produced in volume.

1

No Workpiece Deflection

The regulating wheel provides continuous radial support, eliminating deflection even on long, slender parts. This enables heavier passes and tighter diameter control than between-centers grinding.
2

High-Volume Throughput

Through-feed centerless grinding is a continuous process. Parts feed through the machine without stopping for loading or fixturing, enabling very high production rates for rods, bars, and pins.
3

No Axial Thrust on the Part

Unlike between-centers grinding, centerless grinding applies no end pressure to the workpiece. This is critical for brittle materials like tungsten carbide, where axial thrust can cause cracking or chipping.
4

Excellent Roundness & Straightness

The three-point contact geometry of the work-rest blade, regulating wheel, and grinding wheel produces exceptional roundness and straightness — often superior to between-centers methods.
5

Fast Setup, Quick Changeover

No centers, chucks, or fixtures to set up. Wheel changes to accommodate different diameters or grits are straightforward, keeping changeover time low and machine utilization high.
6

Extended Wheel Life

The floating condition of the workpiece during through-feed grinding distributes wear more evenly across the wheel face, extending wheel life and reducing per-part abrasive cost.

Centerless Grinding vs. Cylindrical Grinding: Which Is Right for Your Part?

Extramet offers both centerless grinding and CNC cylindrical grinding. The right choice depends on your part geometry, volume, and tolerance requirements.

Factor Centerless Grinding CNC Cylindrical Grinding
Workholding No fixture — rests on work-rest blade Held between centers or in chuck
Best For Simple cylinders, rods, bars, pins — high volume Complex profiles, multiple diameters, tight concentricity
Production Speed Very high (continuous through-feed) Moderate (individual part setup)
Brittle Materials Excellent — no axial thrust Possible, but end pressure requires care
Concentricity Good for simple OD Superior for complex multi-diameter parts
Typical Tolerance ±0.0001″ OD Varies by geometry and setup

Not sure which process is right for your application? Contact our team — we will review your print or specification and recommend the optimal approach.

Industries We Serve

Extramet’s precision centerless grinding services support applications where dimensional accuracy and material integrity are non-negotiable.

Aerospace & Defense

Landing gear shafts, guidance system components, turbine blade pins, and fasteners requiring tight OD tolerances and certified quality documentation.

Medical Devices

Surgical instrument components, implant tooling, and precision pins where surface finish and dimensional consistency directly affect patient safety.

Oil & Gas

Valve stems, pump shafts, downhole drilling components, and seal seats that must withstand extreme pressure, temperature, and abrasive environments.

Automotive

Fuel injector components, transmission shafts, hydraulic system parts, and engine valves requiring high-volume consistency and tight diameter control.

Energy

Turbine components, pump shafts, and precision parts for renewable and conventional power generation systems.

Food Packaging

Precision-ground shafts, rollers, and packaging machinery components where hygiene, dimensional accuracy, and corrosion resistance are critical.

Quality Assurance

Extramet Products operates under ISO 9001:2015 certification, which governs our quality management system across all manufacturing and grinding operations. Every centerless ground component is produced and inspected under documented quality procedures designed to ensure dimensional conformance, surface finish consistency, and full traceability.

Our quality system covers incoming material inspection, in-process dimensional verification, and final inspection before shipment. For customers with specific documentation requirements — such as material certifications, dimensional inspection reports, or first-article documentation — please specify these at the time of quoting.

✓ ISO 9001:2015 Certified | ✓ In-Process Dimensional Verification | ✓ Full Material Traceability | ✓ Inspection Reports Available | ✓ Customer-Specific QA Documentation

Centerless Grinding — Frequently Asked Questions

Common questions from engineers and procurement teams about Extramet’s centerless grinding capabilities.

What is centerless grinding?

Centerless grinding is a machining process that removes material from the outside diameter of a workpiece using two rotating wheels — a grinding wheel and a regulating wheel — without the need for a spindle, chuck, or center. The workpiece rests on a work-rest blade between the two wheels. Because no fixturing is required, centerless grinding is exceptionally fast and well-suited for high-volume, tight-tolerance production of cylindrical components.

What is the difference between centerless grinding and cylindrical grinding?

In cylindrical grinding, the workpiece is held between two centers or in a chuck and rotated against the grinding wheel. Centerless grinding requires no fixturing — the part is supported by a work-rest blade and a regulating wheel. This makes centerless grinding significantly faster for simple cylindrical forms and high-volume runs, while cylindrical grinding is preferred for complex profiles, tight concentricity requirements, or parts that cannot be fed through a centerless machine. Extramet offers both centerless grinding and CNC cylindrical grinding services.

What materials can Extramet centerless grind?

Extramet specializes in centerless grinding of tungsten carbide — one of the hardest and most wear-resistant engineering materials available. We grind both our own stock carbide rods and customer-supplied carbide material. Our expertise with tungsten carbide grades ensures optimal wheel selection, coolant strategy, and process parameters to achieve consistent diameters and superior surface finishes without subsurface damage.

What tolerances can Extramet hold in centerless grinding?

Extramet holds tolerances as tight as 0.0001 inches (0.005 mm) in centerless grinding. Our standard stock diameter range runs from 0.038″ – 1.500″. Both polish and regular surface finish options are available depending on application requirements.

What surface finish options are available?

Extramet offers two surface finish options for centerless ground tungsten carbide: a polish finish for applications requiring the smoothest possible OD surface, and a regular finish for applications where a standard ground surface meets specification. Specify your finish requirement at the time of quoting.

Can Extramet grind customer-supplied material?

Yes. In addition to grinding our own stock tungsten carbide rods and blanks, Extramet accepts customer-supplied carbide material for centerless grinding. We maintain the same tight tolerances and surface finish standards regardless of material source.

What are the advantages and limitations of centerless grinding?

The key advantages include no workpiece deflection, high throughput for cylindrical parts, no axial thrust (critical for brittle materials like tungsten carbide), excellent roundness and straightness, and fast changeover. The primary limitation is geometry: centerless grinding works best on simple cylindrical forms. Parts with complex profiles, multiple diameters, or tight concentricity requirements between features are better suited to CNC cylindrical grinding.

Is Extramet ISO certified for centerless grinding?

Yes. Extramet Products operates under ISO 9001:2015 certification, which governs our quality management system across all manufacturing and grinding operations. Every centerless ground component is produced and inspected under documented quality procedures.

How do I request a quote for centerless grinding services?

You can request a quote by visiting our contact page, calling us toll-free at 800-862-7066, or emailing info@extramet.net. To receive the fastest and most accurate quote, please provide your material grade, required diameter(s), length, tolerance, surface finish requirement, and estimated quantity.

Ready to Start Your Centerless Grinding Project?

Tell us your material, diameter, tolerance, and quantity — we’ll respond with a fast, accurate quote.
Customer-supplied carbide accepted. ISO 9001:2015 certified.

Request a Quote
Call 800-862-7066

Related Services

In addition to centerless grinding, Extramet offers a full suite of on-site precision services for tungsten carbide components.

CNC Cylindrical Grinding

Precision OD grinding for complex profiles, multiple diameters, and parts requiring tight concentricity. Ideal when centerless grinding geometry constraints apply.

Precision Surface Grinding

Flat and parallel surface finishing for carbide blanks, plates, and tooling components requiring tight thickness and flatness tolerances.

Laser Etching

Permanent part marking and identification for traceability, branding, and compliance requirements on finished carbide components.

Tungsten Carbide Stock

Extramet stocks a broad range of carbide grades in rod and shape form. Combine material supply with centerless grinding for a single-source solution.
Reviewed by the Extramet engineering team

This page was reviewed for technical accuracy and alignment with Extramet’s current centerless grinding capabilities for tungsten carbide components.
About Extramet | View ISO 9001:2015 Certification