KETOS®
(AISI O1)
 
Ketos is an oil-hardening tool steel which may be hardened from fairly low temperatures with little size change. This grade combines deep-hardening qualities with a fine-grained structure, affording good initial production runs, and good continued production after grinding.
 		  
Typical Chemistry
Carbon 0.90%
Manganese 1.25%
Silicon 0.30%
Chromium 0.50%
Tungsten 0.50%
Typical Applications
  Blanking Dies Jewelers Hobs
  Engraving Tools Paper Knives
  Forming Tools Taps (Hand)
  Gauges Trim Dies
   
Hardening
Note: Full hardness will only be attained in sections less than about 3 inches thick.
 

 Critical Temperature: 1370F(745C).
Preheat: 1250/1350F(675/730C)
High Heat: 1450/1500F(790/815C), hold 10/30 minutes at temperature. Quench: Quench in oil to hand warm, 150F(65C).
Temper: 350/600F(175/315C); hold one hour per inch of thickness, two hours minimum, four hours preferred.
Cryogenic treatments: Refrigeration treatments may improve long-term dimensional stability by transforming retained austenite. Refrigeration treatments should be performed after at least one temper, to minimize risk of cracking, and should always be followed by a temper.
 
    
Typical Properties
 Hardness and Impact Toughness Data
Oil Quenched from 1475F(800C).
 
Tempering
 
Temp.
 
Hardness
HRC
 
 Toughness,
Charpy C-notch
 
°F
 
°C
 
 ft-lbs
 
Joules
 
AQ 63-65 – –
300 150 63-65 14 19
350 175 62-64 28 38
400 205 61-63 30 41
450 230 60-62 – –
500 260 58-60 30 41
600 315 55-57 32 43
700 370 51-53 – –
800 425 48-50 – –
900 480 43-45 – –
1000 540 39-41 – –
     
   
Size Change During Hardening
Hardening
 
Temp.
 
Tempering
 
Temp.
 

HRC
 
Longitudinal
 
Size Change
%
 

°F

°C

°F

°C

1475

800

300

150

64

+.12

1475

800

400

205

62

+.14

1475

800

450

230

61

+.18
     
Surface Treatments
Ketos can be given standard surface treatments such as hard chrome plating if desired. Nitriding is not generally practical due to a substantial loss of core hardness.
Annealing
A. Heat to 1425/1450F(775/790C), hold two hours, cool slowly, 50F(30C) per hour maximum, to below 1000F(540C), then air cool.
OR
B. Heat to 1425/1450F(775/790C), hold 2 hours, cool to 1275F(690C) 6 hours, then air cool.
Typical annealed hardness: 187/221 BHN
Stress Relieving
Annealed Material: 1100/1300F(595/740C), hold 2 hours, cool in still air.
Hardened Material: 50F(30C) below last tempering temperature, hold two hour, cool in still air.
Welding
Use oil-hardening (O1) tool steel filler material.
Annealed material: Preheat to 400/600F(205/315C). Maintain over 400F(205C) during welding. Allow to cool to hand warm (150F(65C) after welding. Reanneal, or temper 1250/1300F(675/705C) for 6 hours.
Hardened material: Preheat to 50F(30C) below tempering temperature (300F(150C) minimum). Maintain over 300F(150C) during welding. Allow to cool to hand warm (150F(65C) after welding. Retemper twice at 25/50F(15/30C) below original tempering temperature.

 Physical Properties
Modulus of Elasticity ...................................................................30 psi x 106 (207 GPa)
Density .......................................................................................0.283 lb/in3 (7850 kg/m3)
Specific gravity ............................................................................................................7.85
Thermal Conductivity ................................... 20 BTU/hr/ft/°F(200F) 34.5 W/m°K(95C)
Thermal Expansion
 		    
 
Temperature
 
Range
 
Coefficient of Thermal
 
Expansion
 

°F

°C

in/in/°Fx10-6

mm/mm/°Cx10-6

RT/400

RT/205

7.0

12.6

RT/800

RT/425

7.4

13.3

RT/1000

RT/540

7.8

14.0

Back to Products