O1 Tool Steel Precision Ground Flat Bar 3/16" x 3/4" (3ft bar)

$71.49 Per Length

3ft Length O1 Grade

Only 4 left in stock

Tax and shipping calculated at checkout.

Thickness

0.19 in"

Width

0.75 in"

Material

Tool Steel

Shape

Flat Bar

Weight

1.43 lb/length

Ships next business day Secure checkout Pickup available

Specifications

Material	Tool Steel
Shape	Flat Bar
Alloy	O1
Thickness	0.19 in"
Width	0.75 in"
Length	3 ft (36")
Weight	1.43 lb/length
Surface	Precision Ground
MTR	Available Upon Request

Characteristics

Weldability	Not Recommended
Machining	Excellent
Bending/Forming	Poor
Wear Resistance	Excellent
Corrosion	Poor

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Description

O1 Tool Steel Precision Ground Flat Bar 3/16″ x 3/4″ (3ft bar) is sold in full lengths as listed, so we don't cut it to size. We ship anywhere in Canada from Dartmouth, NS, or you can pick it up free at our shop. There's a $40 minimum order.

O1 Tool Steel Precision Ground Flat Bar — 3/16" thick × 3/4" wide, sold in standard 3-foot lengths.

O1 is an oil-hardening tool steel known for minimal distortion during heat treatment. With excellent machinability in the annealed state and outstanding wear resistance when hardened, it's the go-to choice for precision flat stock applications.

Common Applications

Die plates and wear plates
Blanking and forming dies
Precision shims and spacers
Machine knives and blades
Custom knife making (blade stock)
Jig and fixture components

Key Properties

Grade: O1 (Oil-Hardening)
Finish: Precision Ground (PG)
Hardness (annealed): ~217 HB
Hardness (heat treated): 60–65 HRC
Tolerance: ±0.001" thickness
Standard length: 3 ft (36")

From the counter

About O1 tool steel

O1 is an oil-hardening tool steel, about 0.9% carbon, that you buy soft, shape, then harden in your own shop to the low 60s HRC with a warm oil quench. It's the classic steel for first knives, punches, and one-off dies because it forgives: it hardens in plain oil instead of a violent water quench, and it moves very little doing it. We stock it as precision-ground drill rod and ground flat bar in 3 ft bars.

Read the full O1 tool steel guide

Why do knife makers start with O1?

Because it forgives. It hardens fully in warm oil, a gentle ride for a thin blade, and it arrives annealed and ground so you can build a knife with a file and a drill press. A 60-62 HRC O1 blade holds a keen edge and teaches heat treating without burning an expensive billet.

How do you harden O1?

Heat to about 1475-1500F, soak, quench in warm oil, and temper right away. Most blades land at 60-62 HRC with a 350-400F temper. Test a coupon from the same bar rather than trusting a chart, since your kiln and oil are their own experiment.