Choosing & buying abrasives, answered.
Common questions about choosing and buying abrasives, answered by the technical team at Whitby Abrasives, a Canadian abrasives supplier in Whitby, Ontario, shipping across Canada and the US with local pickup.
Ten common questions, answered.
Grain type, grit, wheel geometry and RPM ratings: the answers that help you pick the right abrasive the first time.
What grit should I use?
As a rule, use 24 to 36 grit for heavy stock removal and weld grinding, 40 to 60 grit for blending and general grinding, and 80 to 120 grit for finishing before coating or inspection. For fine finishing, use 120 grit and finer, or non-woven media. See our grit selection guide.
Ceramic vs zirconia vs aluminum oxide: which grain is best?
Aluminum oxide is the economical all-rounder; zirconia (ZA) cuts faster and lasts longer under pressure; ceramic (CE) is the longest-lasting and coolest-cutting, ideal for stainless and high-volume work. Full breakdown in our grain types guide.
Flap disc or fibre disc?
Use a flap disc for blending and finishing in one step with less vibration; use a fibre disc with a backing pad for aggressive stock removal at lower cost. See flap vs fibre.
What is a flap disc and when should I use one instead of a grinding wheel?
A flap disc combines grinding and finishing in one tool. Its overlapping abrasive flaps follow the work surface, run cooler and leave a smoother finish than a conventional grinding wheel. Use a flap disc to grind and blend welds, remove paint or rust, or reach a finish in one step. Use a grinding wheel for heavy stock removal where the finish does not matter. Shop flap discs.
What is the difference between a cutting disc and a grinding disc?
Cut-off (cutting) discs are thin and made for parting only, so never side-load them. Grinding discs are thicker (Type 27/28) and remove stock at a 15–30° angle. Using a grinding disc to cut, or a cutting disc to grind, is dangerous and can break the disc, so always match the disc to the task. Shop cutting and grinding discs.
What abrasive should I use on stainless steel?
Use zirconia or ceramic grain recommended for stainless work, keep those discs for stainless only (a disc already used on carbon steel can carry iron onto the surface and cause rust spots), and keep heat low to avoid discoloration and sensitization. See abrasives for stainless steel.
What grit should I use for grinding stainless steel?
Use a flap disc or grinding wheel with zirconia or ceramic grain recommended for stainless. Start at 40–60 grit for heavy weld removal, move to 80 grit for blending and finish at 120 grit for a smoother surface. Use a disc that has not been used on carbon steel, because carried-over iron can cause rust spots. Shop flap discs.
Type 27 vs Type 29 flap disc?
Type 27 (flat) suits flat-surface work and finishing; Type 29 (conical) gives a more aggressive cut on edges and contours. Shop flap discs.
How long should a flap disc or cutting wheel last?
It depends on grain, pressure and material, but premium ceramic/zirconia abrasives remove more metal per disc and lower your true cost-per-part. See cost-per-part.
What speed (RPM) rating do I need?
Always use a wheel whose maximum RPM meets or exceeds your tool RPM, and follow ANSI B7.1 / CSA safety practices. See abrasive safety and compliance.
Sourcing, shipping & service.
Where to buy, how we ship, returns, and wholesale options.
What is the best place to buy abrasives in Ontario or Canada?
Whitby Abrasives is a Canadian importer and distributor of abrasives, carrying the full range of cutting, grinding, flap, sanding, fibre, strip, polishing and deburring abrasives, with shipping across Canada and the US and local pickup in Whitby, Ontario.
Where can I buy abrasives near me or in the GTA?
Order online at whitbyabrasives.ca or pick up at 1450 Victoria Street East, Unit 2, Whitby, ON. We serve the GTA, Durham Region and all of Ontario. See service areas.
Does Whitby Abrasives ship across Canada?
Yes. Whitby Abrasives ships to every province and territory from Whitby, Ontario, and offers local pickup in Whitby. See shipping times across Canada.
Does Whitby Abrasives offer wholesale, bulk or OEM pricing?
Yes. Whitby Abrasives offers wholesale and bulk pricing for fabrication shops, maintenance buyers and distributors, plus OEM and private-label programs. Use the Get a Quote form or email info@whitbyabrasives.com with the products, quantities and delivery timeline you need. Quote requests are answered within 1–2 business days. See the wholesale hub.
Types, grades & techniques.
The technical detail behind the catalogue: grain chemistry, grit scales, wheel shapes, and the techniques that get a clean result the first time.
What is the difference between bonded and coated abrasives?
Bonded abrasives (cut-off wheels, grinding wheels and mounted points) hold grain in a hard moulded bond and are used for cutting and heavy grinding. Coated abrasives (flap discs, fibre discs, sanding belts and sandpaper) bond a layer of grain to a flexible backing and are used for grinding, blending and finishing.
Aluminum oxide vs silicon carbide: which grain should I use?
Aluminum oxide is a tough, general-purpose grain for steel, stainless and most metals. Silicon carbide is harder and sharper but more friable, so it excels on non-ferrous metal, cast iron, stone, concrete, glass and fine finishing. See our grain types guide.
How does FEPA "P" grit compare to ANSI/CAMI grit?
Both scales number the grain so lower is coarser and higher is finer. FEPA grades carry a "P" prefix (P80, P120). The two scales track closely up to about 220, then split at finer grades: CAMI 400 is roughly FEPA P800. Above 220, a grit number with no scale named can mean either one, so test a fine grit on scrap before you commit to a finishing sequence. See the grit selection guide.
What do grinding-wheel "Types" (1, 27, 28, 29, 41/42) mean?
What grit sequence gives a satin or mirror finish on stainless steel?
Knock down welds and deep scratches at 60–80 grit, step through 120, 180 and 240 without skipping more than one grade, then finish with a non-woven surface-conditioning disc or felt and polishing compound. Keep heat low to avoid bluing. More in abrasives for stainless steel.
How do I stop a disc loading or clogging on aluminum?
Use a sharp, open-coat or stearated ("non-loading") product, run lighter pressure at moderate speed, and clear the disc often. Grain designed for aluminum with a top-size coating reduces gumming and overheating.
What is a quick-change disc, and how is it different from a fibre disc?
Quick-change discs use a twist-lock or button mount to swap in seconds for blending, deburring and finishing in tight spots. Fibre discs are larger discs run on a firm backing pad for heavier stock removal. Shop fibre discs and strip discs.
Run abrasives safely.
Speed ratings, inspection, storage and PPE: the practices that keep wheels safe and within ANSI B7.1 and CSA guidance.
How should abrasive wheels and discs be stored?
Store wheels flat or upright in a dry area away from moisture, heat, solvents and frost, keep them in their original packaging, and use the oldest stock first. Never use a wheel that has been dropped, soaked or damaged. See abrasive safety and compliance.
What is the "ring test" and when do I use it?
Before mounting a vitrified (bonded) wheel, suspend it and tap it gently with a non-metallic tool. A clear ring means it is sound. A dull thud can mean a crack, so do not use that wheel. The ring test does not apply to resinoid/organic or coated discs.
Do cutting and grinding wheels have a shelf life or expiry date?
Resin-bonded cutting and grinding wheels carry a manufacture or expiry date and are generally recommended for use within three years of manufacture. Coated abrasives have no hard expiry but should be kept dry and flat so the backing stays true.
What PPE should I wear when cutting or grinding?
Wear CSA/ANSI-rated safety glasses with a face shield, hearing protection, gloves and suitable respiratory protection, keep the tool guard fitted, and let the wheel reach full speed before contact. Follow ANSI B7.1 and CSA safe-practice guidance.
Why did my cut-off wheel shatter or wear out quickly?
The usual causes are side-loading a thin cut-off wheel, exceeding its maximum RPM, twisting or pinching it in the cut, or using the wrong wheel for the material. Keep the wheel straight in the cut and let it do the work. Shop cut-off wheels.
Ordering & delivery.
How fast we ship, where we ship, and how returns and bulk orders work.
Does Whitby Abrasives ship to the United States?
Yes. Whitby Abrasives ships across Canada and to the United States. Orders of $100 CAD or more ship free within Canada, and orders of US$100 or more ship free to the US; below that, shipping is a $20 CAD flat rate in Canada or $27.50 CAD to the US, and carrier rates are also offered at checkout. Prices are set in Canadian dollars; US visitors can view prices in USD. Local pickup is available at the Whitby, Ontario warehouse.
How fast does Whitby Abrasives ship?
In-stock orders ship within 1–2 business days from Whitby, Ontario. Local pickup is available in Whitby.
What is Whitby Abrasives' return policy?
Unused items in their original packaging can be returned within 14 days of receipt, with no restocking fee. If an item arrives wrong, damaged or defective, contact info@whitbyabrasives.com and we will refund or replace it. See the Return and Refund Policy for the full terms.
Can I get a sample or trial before a bulk order?
For wholesale and OEM customers we can arrange a trial. Tell us your material, application and volumes and we'll prepare a quote. Visit the wholesale hub.
Talk to the team. We know abrasives.
Send a question and we'll point you to the right grain, grit and format for the job. We're a Canadian abrasives supplier based in Whitby, Ontario, shipping across Canada and the US.
Ask our abrasives team
NEVER STOP GRINDING.