Gray Iron (Semi Steel)

These gray iron and semi-steel wheels suit hot, abrasive, or high-load carts where soft treads would cut or melt. Wheels in this collection range from about 250 to 5,500 lb per wheel. Semi-steel titles often list about 600°F service. Soft polyurethane on aluminum (~85 Shore A) or TPR is better on finished floors with chips, but hard iron is the better pick for heat and sharp debris. Match bore, width, and diameter to the old wheel before you order. Read the listing for the exact wheel size, overall height, and mount shown. Confirm the load rating printed on the title before you place your order today. Keep the load on the rating for that SKU and do not exceed it in service. Verify the stem or plate matches your old unit before you buy. Read the listing for the exact wheel size, overall height, and mount shown. Capacities below are per wheel as labeled. Broader metal aisle: metal wheels. High-temp aisle: high temperature wheels.

What semi-steel is for

Semi-steel (gray iron) carries heat and abrasion that melt or chip plastic. Use it on foundry carts, welding fixtures, and chip-covered floors. Ductile iron on this page covers the higher load and heat band [S1][S2].

Material	Listed temperature	Loads on this page
Semi-steel (Class 30 gray iron)	About -45 to 600°F	Most of the 83 SKUs; hundreds to 5,500 lb
Ductile iron	Toward 800°F where listed	Higher impact and load band

Active products on this page; temperatures and loads from product fields [S1].

Sizing notes

Match diameter, tread width, bore, and hub length to the worn wheel.
Expect floor marking and a hard ride compared with polyurethane.
For track service, see V-groove iron hubs instead of flat-face semi-steel.

Gray iron wheel questions

What capacity range is on this page?

About 250 lb to 5,500 lb per wheel on active listings.

How hot can these wheels run?

Semi-steel listings commonly show about -45 to 600°F. Some ductile iron listings push toward 800°F. Confirm the product field.

Will gray iron mark my floors?

Yes. Metal treads mark and dent soft coatings. Use polyurethane or nylon when floor finish matters.

Semi-steel or ductile iron?

Semi-steel covers most heat and chip jobs on this page. Pick ductile when the listing shows higher load or the hotter temperature band.

Jordan Wilson, CasterHQ · reviewed October 26, 2026 · 844-439-4335 · info@casterhq.com

Sources

[S1] CasterHQ product fields for gray iron / semi-steel wheels on this page, pulled October 26, 2026.
[S2] Hamilton Caster iron and metal wheels overview (hamiltoncaster.com/Wheels).
[S3] Industry practice: metal for heat and chips; polyurethane when floor finish matters.

BHP: 1-3/4″ × 2-7/8″, slotted to 3″

BHP: 1-3/4″ × 2-15/16″ slotted to 2-3/8″ × 3-3/8″

BHP: 2-5/8” X 3-5/8” (Slotted to 3” x 3”)

BHP: 2-7/16" x 4-15/16" slotted to 3-3/8" x 5-1/4"

(3″ Wide Casters), Industry-Standard

BHP: 3-3/8" x 5-1/4" slotted to 4-1/8" x 6-1/8"

BHP: 4-1/8" x 6" slotted to 4-1/2" x 6-1/8"

View All • 21 Plate Sizes

Plate Casters

Stem Casters

Stainless Casters

Ergonomic Casters

Leveling Casters

Gray Iron (Semi Steel)

What semi-steel is for

Sizing notes

Gray iron wheel questions

Sources