DIN C125W, AISI Approx. W1

Designation by Standards

Chemical Composition (in weight %)

Description
Low alloyed water-hardening tool steel. This steel is one of the common water hardening tool steel grades available. W1 is basically a simple high carbon steel and is easily hardened by heating and quenching in water, just as with plain carbon steel alloys. 

Applications
W1 is commonly used for hand operated metal cutting tools, cold heading, embossing taps and reamers as well as cutlery. For knives, razor blades, cutting tools for machining of steels and metals, broaching tools, tools for screw cutting, chisels, drawing dies, tools for hardest stones. 

Physical properties (avarage values) at ambient temperature
Modulus of elasticity [10³ x N/mm²]: 210 
Density [g/cm³]: 7.85
Thermal conductivity [W/m.K]: 45.0 
Electric resistivity [Ohm mm²/m]: 0.20
Specific heat capacity[J/g.K]: 0.46

Coefficient of Linear Thermal Expansion 10^-6 oC^-1

Soft Annealing
Heat to 680-720^oC, cool slowly. This will produce a maximum Brinell hardness of 213.

Stress Relieving
Stress relieving to remove machining stresses should be carried out by heating to approx. 600-650^oC, holding for 1-2 hours at heat, followed by air cooling. This operation is performed to reduce distortion during heat treatment.

Hardening
Harden from a temperature of 760-790^oC followed by water quenching. Hardness after quenching is 66 HRC.

Tempering
Tempering temperature: See the data bellow.

Tempering Temperature (^oC) vs. Hardness (HRC)

Tempering Diagram

Forging
Hot forming temperature: 1000-800^oC. 

Machinability
W1 is a plain carbon steel and machines with ease. It is the base line of 100% machinability on which machinability of the other tool steels is compared.

Corrosion Resistance 
This is a plain carbon steel and it will corrode unless protected.

Welding 
W1 may be welded by all of the standard techniques.

Disclaimer
The information and data presented herein are typical or average values and are not a guarantee of maximum or minimum values. Applications specifically suggested for material described herein are made solely for the purpose of illustration to enable the reader to make his own evaluation and are not intended as warranties, either express or implied, of fitness for these or other puposes. There is no representation that the recipient of this literature will receive updated editions as the become available.