ASTM A600-92a(2024)
Standard Specification for Tool Steel High Speed

Standard No.

ASTM A600-92a(2024)

Release Date

2024

Published By

American Society for Testing and Materials (ASTM)  US  /  ASTM

Latest

ASTM A600-92a(2024)

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Introduction

Analysis of the core content of the standard

Technical elements	Tungsten high-speed steel	Molybdenum high-speed steel
Typical grades	7 types including T1/T2/T15	19 types including M1/M2/M42
Core alloy	W(17-19%)+V(1-5%)	Mo(5-10%)+Co(8-12%)
Annealed hardness HB	255-302	248-311
Quenching temperature range	2330°F(1277°C)	2150-2240°F(1177-1227°C)

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Key points of chemical composition control

Take M2 high speed steel as an example, its composition control requirements are:

• Carbon content: 0.78-0.88% (conventional type) or 0.95-1.05% (high carbon type)
• Key alloy: Mo 4.5-5.5% + V 1.75-2.2% + W 5.5-6.75%
• Impurity limits: P≤0.03% + S≤0.03% + (Ni+Cu)≤0.75%

Electrofusion process shall be adopted in actual smelting. Composition analysis must be carried out for each heat. The deviation of drill cuttings analysis of finished bars shall not exceed the limit values in Table 1.

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Key technical parameters of heat treatment

Hardening response test requirements specified in the standard:

1. Specimen size: 6.4mm thick disc or 76.2mm long longitudinal specimen
2. Austenitizing: Salt bath furnace (±5°C control) insulation ≥5 minutes
3. Quenching medium: Oil quenching or 566-635°C molten salt quenching
4. Tempering system:
   • Conventional steel: 1025°F(552°C)×2h+2h
   • High cobalt steel: 1000°F(538°C)×3 cycles

Typical grades class=instrument>T15 must meet the hardness requirement of ≥65HRC, and its special tempering system is the key to ensuring red hardness.

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Material selection implementation recommendations

Selection strategy based on processing conditions:

Application scenarios	Recommended grades	Advantageous characteristics
Heavy cutting	M42/M48	High cobalt content (8-10%) provides excellent thermal stability
Precision tools	T1/T15	High tungsten-vanadium combination ensures cutting edge sharpness
Economical tools	M50/M52	Low alloy content, suitable for medium loads

Note: When selecting, it is necessary to consider the balance between design parameters, service conditions and mechanical performance requirements.

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Standard Evolution and Quality Control

Major changes to this standard since its first publication in 1969:

• 1992 Edition: Added new alloy grades such as M48/M62
• 2016 Edition: Improved heat treatment response test methods
• 2024 Edition: Updated referenced standards (such as A388/A388M Ultrasonic Testing Specification)

Three key links in quality control:

1. Macrostructure: Assess central porosity and as-cast structure according to A561 standard, with a maximum allowable rating of 3.5-5
2. Decarburization layer: ≤0.025-0.156mm per side of hot-rolled flat steel (as size increases)
3. Dimensional Tolerance: Cold drawn round steel diameter tolerance ±0.002-0.003 inches

ASTM A600-92a(2024) Referenced Document

• ASTM A370 Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• ASTM A388/A388M Standard Practice for Ultrasonic Examination of Heavy Steel Forgings
• ASTM A561 Standard Practice for Macrotech Testing of Tool Steel Bars
• ASTM A700 Standard Practices for Packaging, Marking, and Loading Methods for Steel Products for Domestic Shipment
• ASTM E3 Standard Practice for Preparation of Metallographic Specimens
• ASTM E30 Standard Test Methods for Chemical Analysis of Steel, Cast Iron, Open-Hearth Iron, and Wrought Iron
• ASTM E45 Standard Test Methods for Determining the Inclusion Content of Steel
• ASTM E59 Sampling practice for determination of chemical composition of steel and cast iron

ASTM A600-92a(2024) history

• 2024 ASTM A600-92a(2024) Standard Specification for Tool Steel High Speed
• 1992 ASTM A600-92a(2016) Standard Specification for Tool Steel High Speed
• 1992 ASTM A600-92a(2010) Standard Specification for Tool Steel High Speed
• 1992 ASTM A600-92a(2004) Standard Specification for Tool Steel High Speed
• 1992 ASTM A600-92a(1999) Standard Specification for Tool Steel High Speed

Standard and Specification