5/32" 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 100—Great for mechanical applications where you don’t need the exacting tolerances of Grade 25.

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.	Dia. Tolerance	Hardness	Specs. Met	Magnetic Properties	Appearance	Pkg. Qty.		Pkg.
Grade 100



		5/32"	-0.0005" to 0.0005"	Rockwell C58 (Extra Hard)	ISO 3290	Magnetic	Mirror Like	100	9529K12	00000


		Grade 25



				5/32"	-0.0001" to 0.0001"	Rockwell C58 (Extra Hard)	ISO 3290	Magnetic	Mirror Like	50	9642K33	0000

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.

Tight-Tolerance Wear-Resistant 52100 Alloy Steel—The diameter of these balls is held to a precise tolerance. They’re made from 52100 alloy steel, also known as chrome steel, which has high levels of carbon and chromium to make them extremely hard and resistant to wear. Often used as bearings, these balls are also hardened to increase their abrasion and impact resistance.

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



	5/32"	-0.005" to 0.005"	Case Hardened	44,000	Tumbled	Rockwell C60 (Extra Hard)	Mirror Like	—	500	96455K73	00000


	Wear-Resistant 52100 Alloy Steel



			5/32"	-0.0001" to 0.0001"	Hardened	295,000	—	Rockwell C60 (Extra Hard)	Mirror Like	—	100	9528K12	0000


			Tight-Tolerance Wear-Resistant 52100 Alloy Steel



					5/32"	-0.00005" to 0.00005"	Hardened	295,000	Ground, Polished	Rockwell C60 (Extra Hard)	Mirror Like	ASTM A295	5	9528K47	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.

Polypropylene—Resistant to swelling when exposed to water, these balls are often used in laboratory applications.

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

PTFE—Offering a nonstick, slippery surface, these PTFE balls are often used as bearings and in ball valves. They offer superior chemical resistance and perform well in extreme temperatures. These balls are also excellent electrical insulators.

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







	Delrin® Acetal

	5/32"	-0.001" to 0.001"	-20	180	10,000 to 11,000	1 to 1.5	White	FDA Standard	100	9614K53	00000




			Polypropylene

			5/32"	-0.002" to 0.002"	Not Rated	180	2,900 to 5,070	0.9	Semi-Clear White	—	500	1974K4	0000


			Wear Resistant







							Nylon

							5/32"	-0.001" to 0.001"	Not Rated	Not Rated	11,200 to 12,300	0.6 to 1.4	Off-White	—	100	9613K14	0000


							Chemical Resistant







											PTFE

											5/32"	-0.002" to 0.002"	Not Rated	500	2,000 to 3,480	3.5	White	—	100	9660K14	00000

Multipurpose 304 Stainless Steel Balls

Whether inside pumps or furnace parts, these balls can be used in any mildly corrosive, high-temperature conditions. Made of 304 stainless steel, they won’t degrade when exposed to mild chemicals and water, even at temperatures up to 1500° F. 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. These balls are made to strict ISO 3290 standards for roundness and surface quality.

Although 304 balls aren’t as wear resistant as 440C balls, they’re easier to fabricate. They’re also nonmagnetic.

Grade 100—Great for mechanical applications where you don’t need the exacting tolerances of Grade 25.

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

								Stainless Steel Balls
	Dia.	Dia. Tolerance	Fabrication	Hardness	Specs. Met	Magnetic Properties	Appearance	Pkg. Qty.		Pkg.
Grade 100



		5/32"	-0.0005" to 0.0005"	Cold Worked	Rockwell C25 (Hard)	ASTM A240, ISO 3290, SAE J405	Nonmagnetic	Mirror Like	100	9291K44	00000

Extra-Hard C2 Tungsten Carbide

Machine long-lasting tools, such as end mills and inserts, with these rods. Tungsten carbide, sometimes called carbide, is harder than our Corrosion-Resistant Tungsten with excellent wear resistance. Its extreme hardness lets cutting edges stay sharp far longer than high-speed steel.

Balls

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



5/32"	-0.0001" to 0.0001"	Polished	Not Rated	Rockwell C75 (Extra Hard)	Not Rated	5	9598K59	00000

Highly Corrosion-Resistant 316 Stainless Steel Balls

Trusted in marine and chemical-processing valves, these balls stand up to some of the most highly corrosive environments. Made of 316 stainless steel, they hold up to sulfuric acid, chlorine, and other harsh chemicals in temperatures as high as 1500° F. They’re a step up from balls made of 304, which have similar strength and temperature performance. 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. They’re made to strict ISO 3290 standards for roundness and surface quality.

Although 316 balls aren’t as wear resistant as 440C balls, they’re easier to fabricate. They’re also nonmagnetic.

Grade 100—Great for mechanical applications where you don’t need the exacting tolerances of Grade 25.

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

								Stainless Steel Balls
	Dia.	Dia. Tolerance	Mechanical Finish	Hardness	Specs. Met	Magnetic Properties	Appearance	Pkg. Qty.		Pkg.
Grade 100



		5/32"	-0.001" to 0.001"	Tumbled	Rockwell C25 (Hard)	ISO 3290	Nonmagnetic	Mirror Like	100	96415K72	00000

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	Construction	Temper Designation	Pkg. Qty.		Pkg.
2017 Aluminum



	5/32"	-0.001" to 0.001"	Solid	T4	100	34665K34	000000

Brass Balls

Strong, corrosion resistant, and conductive, brass balls are often used in plumbing check valves and conductive bearings.

	Dia. Tolerance	Temper Designation	Pkg. Qty.		Pkg.
260 Brass



	5/32"	-0.001" to 0.001"	Not Rated	100	9617K33	00000

Fracture- and Thermal-Shock-Resistant Silicon Nitride Ceramic Balls

Often used to create bearings, silicon nitride ceramic is harder than many types of bearing steel but is lightweight and can be easily polished. It also withstands high temperatures.

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

				Temp.
Dia.	Dia. Tolerance	Sphericity Percentage	Color	Min.	Max., ° F	Performance	Dielectric Strength	Porosity	Compressive Strength, psi	Hardness	Pkg. Qty.		Pkg.



	5/32"	-0.00004" to 0.00005"	99.99995%	Black	Not Rated	1,470	Fracture Resistant, Thermal Shock Resistant	Not Rated	13%	550,000	Rockwell C70	5	9576K28	00000

Borosilicate Glass Balls

Also called Pyrex and Schott glass, this glass resists clouding and pitting and is highly chemical and heat resistant. With a low rate of thermal expansion, it stays dimensionally stable during changes in temperature.

				Temp.
	Dia.	Dia. Tolerance	Sphericity Percentage	Min.	Max., ° F	Color	Pkg. Qty.		Pkg.
Annealed



		5/32"	-0.0002" to 0.0002"	99.90%	Not Rated	400	Clear	50	8996K23	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	Mechanical Finish	Yield Strength, psi	Hardness	Heat Treatment	Pkg. Qty.		Pkg.
Mirror Like



	5/32"	-0.001" to 0.001"	Ground, Polished	120,000	Rockwell C30 (Hard)	Annealed	5	9288K33	000000