Double Disk Grinding

What Is Double Disk Grinding? A Guide for Flat Parts

Double disk grinding finishes both faces of a flat part at once. Two abrasive wheels sit a controlled distance apart, and the part passes between them. Parts come out at the thickness that gap sets. The variation in the incoming material no longer matters. The wheels work opposite faces at once, so the forces balance. Parts come out with consistent thickness, flat faces, and very little added stress.

Automotive drivetrains rely on it for shims, spacers, thrust washers, and lock plates. Each of those parts sets a dimension inside an assembly. At Northern Industrial Manufacturing, we stamp these parts on compound tooling and double disk grind them in the same building. This guide covers how the process works and what it holds. It also shows which parts suit it and how it compares with the alternatives.

How Double Disk Grinding Works

The machine is simple in principle and precise in practice. Everything about double disk grinding comes back to two wheels, a controlled gap, and a steady supply of parts.

Double Disk Grinding Uses Two Opposed Wheels

Two abrasive wheels face each other across a gap. The face of each wheel does the cutting, not the outside diameter. That alone separates double disk grinding from most other methods. One wheel works the top of the part while the other works the bottom. Both faces finish in the same pass, so the part never has to be flipped and run a second time.

Double Disk Grinding Feeds Parts Two Ways

Parts reach the wheels one of two ways. A rotary carrier holds parts in pockets and swings them through the gap. A through-feed system guides parts straight through from one side to the other. Either way, parts keep moving. That is why double disk grinding counts as a production process rather than a batch operation. Automated feeding keeps the line running between operator checks.

Balanced Forces Define Double Disk Grinding

Grinding one side at a time pushes the part in one direction. A magnetic chuck or fixture has to hold it there. Double disk grinding pushes from both sides at once, and the forces cancel. That balance matters most on stamped parts, which carry stress trapped by the cutting in the die. Taking equal stock off both faces keeps that stress in balance and helps the part stay flat after it leaves the machine.

What Double Disk Grinding Holds

Buyers care less about the mechanics than the numbers. Here is what double disk grinding delivers on our line.

Double Disk Grinding Thickness Tolerance Explained

Our double disk grinding line holds a 0.001 inch total thickness tolerance. That means the whole band, not plus or minus. Every part leaves at the thickness the wheel gap sets. Coil steel arrives with its own variation, and thickness shifts from coil to coil. Grinding replaces that variation with the number on the print. For a selective fit family, where thickness steps sit close together, that consistency is what makes the system work.

Double Disk Grinding Controls Flatness and Parallelism

We hold flatness and parallelism to 0.001 inch as well. Flatness describes whether a face lies in a single plane. Parallelism describes how evenly the thickness holds across the part, which the trade usually calls thickness variation. A part can measure the same thickness everywhere and still not be flat, so prints should call out both. Double disk grinding controls them together because it finishes both faces in relation to each other.

Double Disk Grinding Surface Finish in Microinches

Double disk grinding leaves a finish of 10 microinches, or 0.25 micrometer. That suits the large majority of shims, spacers, and thrust washers in transmissions, axles, differentials, and transfer cases. Parts that seal, or run against another surface under load, sometimes need a finer finish. Those may belong on a different process.

Parts Suited to Double Disk Grinding

Not every flat part belongs in double disk grinding. The fit comes down to size, thickness, material, and volume.

Double Disk Grinding Size and Thickness Limits

Our double disk grinding line runs flat, single-layer parts up to 6 inches in size. Thickness runs from 0.060 to 0.200 inch. Parts well inside that window run most efficiently. Very thin parts flex and are harder to hold steady between the wheels. Parts past the size limit simply will not pass through. A part outside that range is not impossible. It usually belongs with a shop built for that work.

Steels That Double Disk Grinding Runs Best

Double disk grinding at our plant runs carbon steel from SAE 1008 through SAE 1095. Lower carbon grades form easily in the press and grind quickly. Higher carbon grades reach greater strength and hardness for parts that carry load or resist wear. We also grind parts that arrive already hardened. A harder surface changes how the wheels cut and how often they need dressing.

Automotive Parts That Need Double Disk Grinding

The common candidates for double disk grinding are parts that set a dimension. Selective fit shims establish bearing preload or pinion depth. Spacers position gears along a shaft. Thrust washers carry axial load and control end play. Lock plates hold a setting in place. In each case the part’s thickness becomes part of the assembly. Any error it carries becomes an error in the finished unit.

Double Disk Grinding Compared With Other Processes

Buyers usually weigh double disk grinding against two other routes. Sometimes they weigh it against buying tighter material instead.

Double Disk Grinding vs. Blanchard Grinding

Blanchard grinding, or rotary surface grinding, grinds one face at a time with parts held on a magnetic chuck. It handles large plates and heavy stock removal well. On thin stamped parts it has a weakness. The magnet pulls a bowed part flat and the wheel grinds a flat face. When the magnet releases, the part can spring back. Double disk grinding never clamps the part flat, which is why it suits thin parts under 6 inches.

Double Disk Grinding vs. Single-Sided Surface Grinding

A single-sided surface grinder finishes one face. The part is then flipped and the second face is ground against the first, a step double disk grinding never needs. That doubles the handling and gives the part two chances to shift. It also means dirt or a burr under the part during the second pass can throw off parallelism. Grinding both faces at once removes those risks and cuts cycle time.

Double Disk Grinding After Metal Stamping

Stamping produces the outline, inner diameter, and tabs with excellent accuracy. The press cannot change the thickness of the steel, and that is the job double disk grinding picks up. Buying precision strip narrows the incoming thickness at a higher price per pound. It still does not correct the flatness the press affects. Grinding after stamping handles both, which is why the two processes so often run together.

What Happens After Double Disk Grinding

Grinding is rarely the last operation. A few steps usually follow before double disk grinding parts reach an assembly line.

Deburring and Edges After Double Disk Grinding

Cutting in the die leaves a burr, and double disk grinding can leave its own edge condition. Deburring and chamfering clean that up so parts stack evenly and handle safely. If burrs must come off or an edge needs a chamfer, put it on the print. The operation is cheap to add at the start and expensive to add later.

Color Coding Parts After Double Disk Grinding

Selective fit families hold the same double disk grinding part in a series of thickness steps. Neighboring steps look nearly identical on the line. We can color code selective, series, and family parts with more than ten colors, applied on the outside diameter. That helps assemblers identify parts that look alike. More than one color can go on a single part, which expands how many steps a family can carry.

Buying Double Disk Grinding Services

A short conversation and a complete print will tell a supplier whether double disk grinding fits your part.

What a Double Disk Grinding Quote Needs

A double disk grinding quote starts with the current print, carrying thickness, flatness, parallelism, and surface finish as separate callouts. Add the material grade, any hardness requirement, and an accurate estimate of annual volume. Note any finishing the part needs, such as deburring, chamfering, media finish, or color coding. With that package, a supplier can quote on the first pass instead of coming back with questions.

Double Disk Grinding Volumes and Lead Times

Our double disk grinding programs start above 5,000 pieces per year and run into the hundreds of thousands annually. Because we stamp and grind under one roof, lots never wait for freight or another shop’s queue. In many cases we deliver in under two weeks. Parts are made in the USA, so buyers pay no import tariffs and can source locally.

Double Disk Grinding at Northern Industrial Manufacturing

Double disk grinding turns a stamped blank into a part an assembly can trust. It brings every piece to a common thickness and holds flat, parallel faces. It does that fast enough for automotive volumes. For shims, spacers, thrust washers, and lock plates, nothing else holds a 0.001 inch total thickness tolerance across millions of parts as practically.

Northern Industrial Manufacturing Corp. stamps on compound tooling and double disk grinds to 0.001 inch thickness, flatness, and parallelism. We also deburr, media finish, and color code in one IATF 16949 certified plant in the Detroit area. General Motors has recognized our quality with its Supplier Quality Excellence Award in 11 of the past 13 years. Send us your print. Our team will tell you whether double disk grinding fits your part and what it takes to run it.

Double Disk Grinding Manufacturer

Northern Industrial Manufacturing is your premier parts manufacturer for double disk grinding services. With a reputation for the closest tolerances, highest product quality, short lead times, process innovations, and technical prowess – we can meet your double disk grinding manufacturing needs, while exceeding your expectations and delivering your parts on time and on budget.

If your manufacturing needs calls for precise, dependable double disk grinding, the team at Northern Industrial Manufacturing is ready to support you. Call 586.468.2790 or request a quote today to discuss your project and discover how our double disk grinding services can support your production goals.

Precision Double Disk Grinding Services: 586.468.2790