O1 Tool Steel Grade Shapes, Sizes, and Technical Information From Tool Steel Service Inc.

O1 Tool Steel is a very popular and highly versatile oil-hardening cold-work tool steel. Type O1 steel consist of small amounts of manganese, tungsten, and chromium which gives it adequate toughness for a variety of tool and die applications. We stock O1 Tool Steel in a wide variety of shapes and sizes.

O1 Tool Steel Shapes, Sizes, and availability

Below is our stock sizes and availability for O1 Tool Steel. Special sizing, cutting, and grinding are available upon request.

Stock Sizes

O1 Decarb Free Rounds are available in 1/4" to 20-1/4" diameter.


Rounds Bars are supplied decarb free and sufficiently over-size to finish to a diameter ordered in sizes from ¼” to 20-1/4” diameter. Drilling, boring, turning, cutting and centerless grinding services available. Hollow bar supplied in all O.D. sizes shown, with I.D. furnished to any specifications. Pre-Finished Flats and Squares supplied decarb free, ground top and bottom +.015” / .035”, saw cut width +.015 / .065”. Surface Finish 100RMS maximum. Surface grinding service available. Drill Rod and Ground Flat Stock avail in a wide range of sizes. Forgings and Non-Standard Sizes available on special order.

O1 Tool Steel Grade Technical Specifications

Below is the technical specifications for our O1 Tool Steel.

Typical Analysis of O1 Tool Steel

Typical Analysis
C Mn Si Cr V Mo
0.95% 1.20% 0.30% 0.50% 0.20% 0.50%

C - Carbon, Mn - Maganese, Si - Silicon, Cr - Chromium, V - Vanadium, Mo - Molybdenum

General Characteristics of O1 Tool Steel

General Characteristics
Highly versatile and easy to handle in every respect, O1 has long been considered the general purpose tool room steel. Low hardening temperatures allow in-plant heat treatment even where facilities are limited, saving time and expense. Available in a wide variety of sizes and shapes, O1 is a practical selection for many tooling and maintenance applications.

Typical applications of O1 Tool Steel

Typical Applications
Blanking, forming, drawing, molding, trimming dies, spindles, thread gauges, collets and stamps.

Heat Treatment of O1 Tool Steel (In Fahrenheit )

Heat Treatment (degrees in Fahrenheit)
Forging Annealing Preheating Hardening Tempering
1925 to 1500 1400 to 1440 1200 to 1250 1450 to 1500 350 to 450

Effects of tampering of O1 Tool Steel ( In Rockwell C ) In a table, Place the information here

Effects of Tempering (Measured in Rockwell C)
As hardened 400 °F 600 °F 800 °F 1000  °F
63 to 65 61 to 63 55 to 57 48 to 50 39 to 41

O1 Tool Steel Inventory

O1 Precision Ground Flat Stock Standard Tolerance Inventory
O1 Precision Ground Flat Stock Oversize Tolerance Inventory
O1 Drill Rod Inventory
O1 Decarb Free Rounds
O1 Decarb Free Plate


Order O1 Tool Steel today

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