Main characteristics and applications

VR300 is a pre-hardened steel with excellent hardening penetration up to thickness 600mm. To be used for plastic dies with excellent surface finishing properties, compression moulding, plastic injection moulds, moulds for automotive industry with texturing.

VR300 is designed to provide improved performance and offers the following advantages:
• uniform hardness across the full thickness up to 600mm.
• high polishability.
• high machinability.
• excellent suitability for texturing.
• greatly increased thermal conductivity.
• good toughness.

Comparable standards


Chemical composition (typical; in weight %)

CSiMnP (max)S (max)CrMoNi

Production technology

EAF – LF – VD - Forging – Rolling - Heat treatment QT

US specification

In according to standard EN10228-3 Class 4 and standard SEP 1921 Class E/e

Delivery condition

VR300 is delivered in quenched and tempered condition, with hardness range 280 - 325 HB (29 - 35 HRC).

Through hardenability

The high performance of hardenability for thickness 600 mm, is obtained by an optimized balance of chemical composition and a special manufacturing process.


Physical properties (reference values)

Thermal expansion coefficient (10-6/K)1111.612.113.8
Thermal conductivity (W/mk)40.039.338.435.2
Young modulus (Kn/mm2)205201--

Heat treatment

AnnealingHeat to 650 - 700 °CMin. H.T. for 2 minute /mmAir or furnaceIn order to obtain hardness lower than 250 HB ( 24 HRC) to improve machinability
Stress relievingHeat to 500 - 550 °CMin. H.T. for 2 minute /mmAir or furnaceTo be carried out after machining, is recommended to eliminate the residual stresses induced by mechanical working
HardeningHeat to 860-900°CMin. H.T. for 1 minute /mmPolymer-
TemperingIn the range 530 – 610°CMin. H.T. for 3 minute /mmAir or furnaceTo be carried out after hardening. 2nd Tempering must be performed to max 30°C below tempering temperature

C.C.T. curve


Mechanical properties


Tempering curve


Polishing Range

vr300-polishing-range-img vr300-polishing-range2-img

Texturing Samples

Texturing performed by Standex Mold-tech with patterns Standex MT 9086, MT 9055 and 9083


Tool and Die Steel Includes Cold Work Steel, Hot Work Steel, Plastic Mould Steel, High Speed Steel. These tool materials adhere to great quality demands of steel like temper, strength, toughness, resistance to tempering, hardening capacity, dimensional stability etc. The range of Tool Steel in our store includes products from renowned manufacturers.