M-4 High Speed Tool Steel


M-4, like M-2, is a high speed molybdenum tool steel but with a high vanadium content as well to improve wear resistance and toughness

Analysis:

C CO CR MN MO NI P S SI V W
1.25 - 0.14 3.75 - 4.750.15 - 0.404.25 - 5.50 0.20 - 0.453.75 - 4.505.25 - 6.50

Size Availability:

Flats • Hollowbar • Metric • Non-Standard • Rounds • Squares • Standard

Applications:

BroachesBurnishing RollsCutoff Tools
Forming RollsForming ToolsLathe Tools
Milling CuttersPlaner ToolsPunches
ReamersRoll Turning ToolsTwist Drills

Designations:

AISI M4 High Speed Steel-US
ASTM A600-US
FED QQ-T-590-US
SAE J437-US
SAE J438-US
UNS T11304-US

TreatmentTemperature RangeCooling/QuenchingNotes
Forging1900-2000° FSlow.Do not forge below 1700° F. Anneal after forging.
Annealing1550-1600° FCool slowly at a rate of 35° F per hour to 1000° F.For best results, insulating media is desirable. Hold at temperature for 2 hours.
Stress Relieving1100-1300° FCool slowlyStress relieve after rough machining
Preheating1500-1550° FPreheat time in furnace is ¾ Hr. per inch of thickness. Heating up to temperature as slow as possible.
Hardening2150-2250° F (furnace) 2150-2225° F (salt bath)Quench in air or warm oil. To minimize quenching strains, quench in salt at 1000° FFor maximum wear resistance, harden at 2250° F. For maximum toughness and high hardness, harden at 2150° F.
Tempering(See Chart)Double tempering is recommended. The usual tempering time is 2+2 hours. Recommended temperature is 1000-1150° F.
Data is typical and should not be construed as actual values for any category.
Applications and technical information require engineers and tool designers to exercise independent judgement.