DeWalt HP Metal Grinding Wheels Type 27

Why I reached for this wheel

I still keep a couple of 4-inch grinders on the rack, and finding good consumables for them can be a chore. That’s partly why I put the DeWalt Type 27 wheel into regular rotation—curiosity, necessity, and the promise of reliable, heavy stock removal in a size that’s increasingly overlooked. After several weeks of shop work—weld blending on mild steel, edge prep on structural, and some cautious passes on aluminum—I have a solid sense of where this wheel shines and where it’s merely adequate.

Setup and compatibility

The dimensions are straightforward: a 4-inch diameter, 1/8-inch thick, Type 27 (depressed center) profile with a 5/8-11 arbor, rated to 15,200 RPM. That fits the majority of small US-market grinders that still support 4-inch discs—just verify your guard is sized correctly, because a lot of current grinders and guards are set up for 4-1/2-inch wheels. The depressed-center profile is helpful when you’re working into fillets or around weld toes without riding hard on the flange.

I ran the wheel primarily on an 11,000 RPM, 7-amp grinder. Mounting was uneventful—the wheel was true out of the sleeve, no wobble, and the balance felt good. As always, check for handling damage and respect the wheel’s expiration and speed rating. Even with three fiberglass sheets reinforcing it, you don’t want to push your luck.

How it cuts on steel

This is a 24-grit aluminum oxide wheel with a high grain concentration, and it behaves like it: aggressive, eager to bite, and not shy about throwing sparks. On mild steel brackets and angle, it hogs material quickly at a 20–30 degree approach. I used it to take down 3/8-inch fillet weld caps and to rough-bevel 1/4-inch plate. It tracks straight, doesn’t chatter, and holds its corner well enough that I could feather transitions without scalloping the parent metal—provided I kept my angle consistent and avoided leaning the wheel onto its edge.

Compared with a 1/4-inch thick grinding wheel, the 1/8-inch thickness feels faster and livelier. You get less friction and less brute stalling under load. The trade-off is that you have to be a bit more disciplined about side pressure and not use it like a prying tool; it’s a grinding wheel, not a cutter or a paddle. Keep it inside that 15–35 degree window and let the abrasive do the work.

On hot-rolled scale and galvanized remnants, it clears contamination quickly. If you need a “paint-ready” finish, you’ll still want to follow up with a flap disc; 24 grit leaves visible striations, as expected.

Stainless and harder alloys

Aluminum oxide isn’t my first pick for stainless; ceramic or zirconia alumina wheels typically hold an edge longer and resist glazing when you’re pushing hard on austenitic grades. That said, this DeWalt wheel stayed surprisingly consistent on 304 and 316 TIG welds. It does warm up faster and can smear if you flatten the angle to chase a fine blend, but with moderate pressure and a slightly steeper approach, it’ll get you through weld leveling and edge chamfering without burning the work. If stainless is your primary workload, there are faster, longer-lasting options; for occasional stainless, this wheel is perfectly serviceable.

Non-ferrous work

On aluminum, the behavior is what I expect from aluminum oxide: it will load if you run it flat and heavy. Using a wax stick mitigates that; so does keeping the angle on the steeper side and being diligent about clearing the face against a sacrificial piece of scrap when you feel the cut slow. For bronze and brass, it’s more forgiving. I wouldn’t call this a go-to wheel for daily aluminum fabrication, but it can pinch-hit for spot tasks if you bring a lubricant and a light touch.

Control, feel, and heat

This wheel feels well bonded and stable. It doesn’t transmit buzzy, high-frequency vibration through the grinder, which helps with control over longer sessions. The spark stream is bright and plentiful—no surprise at 24 grit—and the workpiece heat is manageable as long as you keep the wheel moving. If you park it to excavate a deep crater, you’ll build heat quickly and risk temper discoloration on thin stock. That’s not a knock on this wheel; it’s the nature of coarse grinding.

Noise is typical for a hard-bonded 24-grit wheel. Good hearing protection is a must, and I’d keep a full guard on—always. It throws a hearty stream of sparks.

Wear and wheel life

DeWalt calls out three full sheets of fiberglass reinforcement, and durability tracks with that claim. I did not experience chunking, sidewall cracking, or premature glazing. Wear is neither particularly slow nor particularly fast—about right for a mid-grade aluminum oxide wheel. Compared with ceramic wheels, it wears faster; compared with bargain-house abrasives, it lasts longer and stays more consistent across its usable diameter. The last third of the wheel still cuts cleanly, which tells me the bond and grain distribution are dialed reasonably well.

If your shop chews through consumables, the economics get better in the 25-pack. For a lighter-use user with a 4-inch grinder, one wheel can cover a surprising amount of welding and prep before it’s toast.

Safety notes

• Max 15,200 RPM gives ample headroom for typical 4-inch grinders, but check your tool speed and guard.
• It’s a Type 27 wheel—don’t side-load it like a flap disc and don’t use it as a cutoff wheel. Get a Type 1 for cuts.
• Inspect before use; resin-bonded wheels have a shelf life. Store them dry, flat, and away from heat.

The reinforcement inspires confidence. I deliberately pushed into some ugly, intermittent welds to test stability and got no alarming behavior—no sudden digs, no chunk-outs—just a predictable bite.

Where it fits in the lineup

If I map this wheel against the broader abrasive landscape:

• For fast removal on mild steel with a standard grinder: it’s a workhorse.
• For stainless as a primary material: it’s adequate, but ceramic or zirconia will run cooler and last longer.
• For aluminum and soft non-ferrous: use sparingly with lubricant to avoid loading.
• For finish work: follow with a finer grit or flap disc after this wheel does the heavy lifting.

The 4-inch size is a quiet advantage in tight spots. The smaller diameter gives you a bit more control in corners and inside frames, and the depressed center helps keep the guard clear while you reach a weld toe.

What I’d change

• I’d love a clearly marked stainless-optimized variant in the same form factor for shops that bounce between mild and stainless daily.
• A grit option around 36 or 40 would create a nice bridge for users who want fewer steps between roughing and finishing.
• Wider single-pack availability would help casual users who don’t need a case.

Tips for getting the best from it

• Run a 20–30 degree angle and moderate pressure; don’t stall the grinder.
• Keep it moving to manage heat, especially on thinner sections.
• For aluminum, use a wax stick and clear the face periodically.
• Swap to a flap disc for blending after the heavy stock removal is done.

Verdict and recommendation

I recommend this DeWalt wheel for general-purpose metal grinding, especially if you’re maintaining older 4-inch grinders or working in tighter spaces where a 4-1/2-inch disc feels clumsy. It removes material quickly, stays stable as it wears, and offers predictable control over fillet welds, edges, and flat stock. The 1/8-inch thickness strikes a nice balance: faster and more responsive than a 1/4-inch wheel, but still sturdy enough for day-in, day-out weld leveling when used correctly.

If your workload is heavily stainless or non-ferrous, you may want to supplement with ceramic or non-loading wheels. For everyone else—fabricators, maintenance techs, and small shops looking for a reliable, aggressive grinder wheel in a harder-to-find size—this is a sensible, trustworthy pick.