2mm Balls | McMaster-Carr

The best choice for high-performance bearings and valves, these 440C stainless steel balls are among the strongest, hardest, and most wear-resistant we offer. They’re passivated to wash away surface particles that cause rust, and they’re polished to a mirror-like finish that contaminants can’t stick to. The result is balls that stay smooth and stand the test of time—even at temperatures up to 800° F. They’re made to strict ISO 3290 standards for roundness and surface quality.

These balls are magnetic, so you can use them in separators, sensors, and automated handling systems that use magnetic pickup or positioning.

Grade 25—Precision-ground to tighter tolerances than Grade 100 balls. Use them in high-accuracy assemblies.

Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.

							Stainless Steel Balls
	Dia., mm	Dia. Tolerance, mm	Hardness	Specs. Met	Magnetic Properties	Appearance	Pkg. Qty.		Pkg.
Grade 25



		2	-0.0025 to 0.0025	Rockwell C58 (Extra Hard)	ISO 3290	Magnetic	Mirror Like	250	1598K18	00000

Steel Balls

Multipurpose Low-Carbon Steel—Low-carbon steel balls are our easiest steel balls to machine. They are often used for parts that don’t require high strength, such as knobs. These balls can be surface hardened with heat treating for added wear resistance.

Wear-Resistant 52100 Alloy Steel—High carbon and chromium content makes this 52100 alloy steel extremely hard and resistant to wear. It’s also known as chrome steel. Often used as bearings, these balls are hardened for increased abrasion and impact resistance.

Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.

	Dia. Tolerance, mm	Heat Treatment	Yield Strength, psi	Mechanical Finish	Hardness	Appearance	Pkg. Qty.		Pkg.
Multipurpose Low-Carbon Steel



	2	-0.13 to 0.13	Case Hardened	44,000	Tumbled	Rockwell C60 (Extra Hard)	Mirror Like	1,500	96455K124	000000


	Wear-Resistant 52100 Alloy Steel



			2	-0.0025 to 0.0025	Hardened	295,000	—	Rockwell C60 (Extra Hard)	Mirror Like	100	9292K31	0000

Plastic Balls

Delrin® Acetal—Able to hold tight tolerances, these balls resist expanding when exposed to heat and moisture. They have a naturally slippery, wear-resistant surface. Use them for bearings and low-load rolling applications. Delrin® acetal resin is also known as acetal homopolymer.

Nylon—Use these nylon 6/6 balls as bearings and in sealing applications. They have a slippery surface that reduces wear caused by friction.

	Max. Temp., ° F	Tensile Strength, psi	Impact Strength, ft·lbf/in	Color	Food Industry Std.	Pkg. Qty.		Pkg.
Multipurpose







	Delrin® Acetal

	2	-0.0254 mm to 0.0254 mm	-20	180	10,000 to 11,000	1 to 1.5	White	FDA Standard	100	9614K71	00000


	Wear Resistant







					Nylon

					2	-0.002" to 0.002"	Not Rated	Not Rated	11,200 to 12,300	0.6 to 1.4	Off-White	—	100	9613K49	0000

Aluminum Balls

2017 Aluminum—An economical choice when you need high strength.

Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.

	Dia. Tolerance, mm	Construction	Temper Designation	Pkg. Qty.		Pkg.
2017 Aluminum



	2	-0.025 to 0.025	Solid	T4	100	34665K36	000000

Extra-Hard C2 Tungsten Carbide

Tungsten carbide, sometimes called carbide, is harder than Corrosion-Resistant Tungsten with excellent wear resistance. Use it to machine long-lasting tools, such as end mills and inserts.

Balls

Dia. Tolerance, mm	Mechanical Finish	Yield Strength	Hardness	Temper Rating	Pkg. Qty.		Pkg.



2	-0.0025 to 0.0025	Polished	Not Rated	Rockwell C75 (Extra Hard)	Not Rated	5	9686K82	000000

High-Strength Grade 5 Titanium Balls

Grade 5 is the strongest of all the titanium alloys thanks to its higher aluminum and vanadium content. It offers a versatile mix of good corrosion resistance, weldability, and formability. These balls are made to Grade 200 tolerances.

Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.

	Dia. Tolerance, mm	Mechanical Finish	Yield Strength, psi	Hardness	Heat Treatment	Pkg. Qty.		Pkg.
Mirror Like



	2	-0.025 to 0.025	Ground, Polished	120,000	Rockwell C30 (Hard)	Annealed	5	9288K102	000000

Tumbling Media for Steel, Stainless Steel, and Hard Metals

Ball

Made of a hard material, this tumbling media is tough enough to finish steel, stainless steel, and other hard metal parts. Choose the shape that best matches the contours of your part and a size that’s large enough not to get stuck in recesses and holes. You can also mix shapes and sizes to tailor the finish to your part.

For Mirror Finish—Use this media as the final step in your finishing process to create a reflective finish. Ideal for fragile parts, it rubs the surface without removing material.

Ball—Best for gentle finishing. Balls are less aggressive than other shapes, so they smooth your workpiece without flattening any details.

Wet Tumbling Condition—Use this media with liquid cleaners.

							5 lb.
	Dia., mm	Density, lb/ft³	Recommended Media to Parts Ratio	Abrasion Type	Tumbling Condition	Material		Pkg.
For Mirror Finish







				Ball

				2	125	3:1	None	Wet	Porcelain	4334A32	000000