Centerless Thru-Feed & In-feed Grinding

Efficient, High-Volume Grinding for Precision Cylindrical Parts

What Is Centerless Thru-Feed & In-Feed Grinding?

Centerless grinding is a process that removes material from the outside diameter of a workpiece using abrasive cutting, but unlike traditional cylindrical grinding, it does not require the workpiece to be held or supported at its center by a spindle or fixture. Instead, the workpiece is positioned between two rotating wheels—a high-speed grinding wheel and a slower-speed regulating wheel—along with a work-rest blade that supports the workpiece from below.

There are two main types:

Through-feed grinding: The workpiece passes completely through the grinding wheels, suitable for simple cylindrical shapes.
In-feed (plunge) grinding: The workpiece is fed radially into the wheels, allowing for more complex shapes or parts with shoulders.

Centerless grinding is widely used for producing high-precision cylindrical parts such as:

Shafts
Pins
Valves
Tappets
Bushings
Rods

Centerless Thru-Feed & In-Feed Grinding: Ideal For Low Volume And High-Volume With Precise Results

Our centerless grinding services are designed to provide fast, efficient, and accurate grinding for parts. We can grind longer parts with ease and hold tight tolerances, ensuring your parts are produced efficiently and to exact specifications. Centerless grinding provides exceptional finishes and tight OD tolerances often required after CNC Swiss Turning of precision machined components.

0.125 to 4 inch diameter
Tolerances to 0.0001 inch diameter, finishes to 8 Ra, roundness < 0.0001 inch

With a variety of specialized centerless grinding machines, we can meet demanding requirements for low-volume, and high-volume production runs.

Cincinnati 350-20 RK Twin Grip – Thru-feed
Cincinnati 340-20 Twin Grip – Thru-feed with part loading automation
(2) Cincinnati 220-8 – Thru-feed
(4) Cincinnati #2 – Infeed/Plunge
Cincinnati 325-12 – Infeed/Plunge
Cincinnati Cinco-15 – Infeed/Plunge

Is CPG’s Centerless Grinding Right for Your Application & Industry?

CPG’s centerless thru-feed and in-feed grinding services are ideal for industries like automotive, medical device manufacturing, and industrial equipment, where precision is critical for parts like bushings, pins, and rollers. CPG provides green grinding prior to surface finish treatment along with finish grinding after surface treatment to exact final tolerance requirements.

If you’re looking for fast, precise grinding for cylindrical parts, our centerless thru-feed and in-feed grinding solutions can meet your needs with proven reliability and performance.

Part type: Spool Bushing

Industries: Agriculture, Auto/Transportation, Building/Construction Equipment, Military/Defense Equipment, Oil & Gas Services, Recreational Vehicle/Power Sports

Applications: A hydraulic spool valve is a crucial component in hydraulic systems, acting as a directional control valve that regulates the flow of hydraulic fluid by shifting a cylindrical part called a spool within the valve body.

Part type: Socket Push Rod- Centerless Infeed/Plunge

Industries: Agriculture, Auto/Transportation, Building/Construction Equipment, Military/Defense Equipment, Oil & Gas Services, Recreational Vehicle/Power Sports

Applications: Pushrods transmit motion from the camshaft to the rocker arms, which in turn open and close the engine valves. Used in the valve train of internal combustion engines.

Part type: Shoulder Bolt – Centerless Infeed/Plunge

Industries: Agriculture, Auto/Transportation, Building/Construction Equipment, Military/Defense Equipment, Oil & Gas Services, Recreational Vehicle/Power Sports

Applications: Precision shoulder bolts are high-accuracy fasteners designed for demanding applications requiring precise alignment, smooth motion, and reliable load-bearing capabilities.

Part type: Hydraulics Spool – Centerless Thru -Feed

Industries: Agriculture, Building/Construction Equipment, Military/Defense Equipment

Applications: Hydraulic spools are vital for controlling the direction and flow of hydraulic fluid, enabling various functions in a wide range of machinery and equipment.

Part type: Pivot Pin – Centerless Thru-Feed

Industries: Agriculture, Building/Construction Equipment, Military/Defense Equipment

Applications: Precision pivot pin is a specialized pin designed and manufactured with high accuracy to function as a crucial element in various hinge and rotational mechanisms.

What Our Customers Say

"Custom Production Grinding has been a valued partner in our supply chain for more than 15 years. They always deliver a quality product at a reasonable price in a timely manner. The staff is knowledgeable, dedicated and always willing to help us out of what is seemingly some hard-to-meet deadline requests. I would recommend Custom Production Grinding to anyone looking to have grinding done to a job. In my mind, they are second to none."

"Thank you and your team for the quick turnaround on the shaft project. I had a lot of pressure on getting these completed, with it being such a high-profile project for us, and of course by the time you got the parts there was no time to spare. Somehow I always worry, but somehow you guys always come through for me! In times like this it reminds me why I consider you a partner vs. just another one of my suppliers."

"I have been using CPG for more than 20 years for my grinding needs. I have always been very satisfied with their professionalism, quality and attention to detail. They truly have a sense of urgency when it comes to servicing each job. They will go above and beyond to get the job done when we need it, and they are one of the most competitively priced grinders in southeastern Wisconsin. I would recommend them for any grinding projects – whether it’s a small quantity, or large production run."

"I’ve been in supply chain management more than 30 years and am pleased to share that Custom Production Grinding is by far one of the most outstanding vendors I have worked with to date. Their staff is extremely easy to work with and does their utmost to achieve our sometimes unreasonable goals; it could be a move-up in a delivery promise, a same-day quote request, an explanation of said quote, or collaboration on a difficult solution or corrective action. I would gladly recommend their organization for your production grinding needs."

"CPG has been grinding our parts since the start of our company in 1997. They have earned our business and trust over the decades. The quality we received from them has been second to none and we know they will grind the job right. Their staff has a great understanding of our products and guide us in ways to produce our parts to help cut costs in the grinding process. We have been in rush situations with no time to go through the quoting process and just sent them the parts to be ground. Because of their integrity, we know we will be treated fairly. They are a great partner to us."

"We’ve worked with CPG for more than 15 years. They are a trusted partner in exceeding our customers' expectations!"

"We have been doing business with CPG for over 38 years. They have been a strategic part of our supply chain since they opened. They are easy to work with and extremely accommodating to our due dates, with quick turnaround times. They produce quality parts and have great attention to detail."

Ready to Improve the Precision of Your Cylindrical Parts?

Get a free quote and discover how CPG’s grinding solutions can help optimize your manufacturing process and improve the quality of your metal or plastic parts.

Let’s Talk About Your Specific Requirements