Machining Materials Guide

Type General Characteristics Alloy Common Applications Tolerances for a 1/2" Dia. Bar Material Cost Factor Machining Cost Factor
Brass
Low cost, low strength, heavy, free machining
CDA 360
Electronic hardware and contacts, fittings, numerous commercial products
+/-.0015 2.5
(High scrap return provides cost savings )
.6
Copper Alloys
Excellent electrical conductivity
TeCu, CA 145
Electrical contacts
+/-.0015 5.4 .7
Higher strength and excellent electrical conductivity
BeCu alloy 25
Electrical contacts
+/-.002 (Can be ordered to +/-.0002 ) 30.0 .75
Aluminum
Designed for machining
2011
Electronic hardware, endless commercial products
Cold finish
+/-.0015
1.6 .6
Improved strength
2024
Electronic hardware, aircraft components
+/-.0015 2.2 .7
Good formability, weldability, and corrosion resistance
6061
Electronic hardware
Cold finish
+/-.0015

Extruded
+/-.009
0.8 .75
Higher strength
7075
Aircraft components
+/-.0015 2.3  
Steel
Plain low carbon steel, poor machinability but good formability and weldability. Case harden only
1018
Rivets and parts requiring strong welds
Cold drawn
+.000/-.002
0.75 3.0
Designed for good machinability
Case harden only
1215
Parts needing better formability or weldability than 12L14
Cold drawn
+.000/-.002
0.95 1.5
Designed for excellent machinability
Case hardening only
12L14
Endless commercial products; probably more pounds used in turned products than any other bar stock
Cold drawn
+.000/-.002
1 1
Excellent machinability w/o lead (Biadded)
Case hardening only
1215 Bi
Same as 12L14, non-leaded replacement for 12L14
Cold drawn
+.000/-.002
1.1 1
Higher carbon, higher strength, direct hardening
1137
Higher stress applications, gears, shafts, studs, etc.
Cold drawn
+.000/-.003
1.25 2.5
Alloy Steel
Direct hardening
4140 or 4142
Higher stress applications needing the strength of an alloy
Cold drawn
+.000/-.003
1.25 3.0
Designed for better machining w/lead additive; direct hardening
41L40
Higher stress applications needing the strength of an alloy
Cold drawn
+.000/-.003
1.4 2.7
.55% Ni, .50% Cr, .20% Mo, heat treatable and case hardening
8620
High stress applications needing the strength of an alloy.
Cold drawn
+.000/-.002
1.8 2.7
Very high 1% carbon, .25% Ni,1.4% Cr, .08% Mo
52100
Bearing applications
Cold finished

Spheroidize annealed
+/- .006
2.0 5.1
Stainless Steel
Designed for machining, non-magnetic
303
Electronic hardware, automotive, aerospace, medical instruments, and many applications requiring corrosion resistance
Cold finished
+/- .002
4.5 2.7
Better weldability and formability, slightly more corrosion resistant
304
Applications needing formability or weldability
Cold finished
+/-.002
3.7 5.0
Better corrosion resistance
316
Medical implants and surgical instruments, aerospace
Cold finished
+/-.002
4.3 5.6
Free machining; less corosion resistant than 300 series; can be heat treated
416
Applications that need less corrosion resistance, more hardness, or lower cost
Cold finished- annealed
+/-.002
3.8 2.6
High carbon, can harden to RC 60
440
Applications requiring stainless steel with highest hardness
  5.9 5.0
Excellent corrosion resistance and heat treatable
17-4 PH
Medical, aerospace, applications needing corrosion resistance and hardness
+/-.002 4.4 5.0
Titanium
High strength, light weight, good bio-compatibility
Ti-6Al-4V
Ti-6Al-4VEli
Aircraft
Medical implants
Ground & polished
+/-.002
21.3 6
Plastics
Low cost plastic
PVC
Gray color
Insulators
Ground
+/-.003
0.9 .8
Good machining
Nylon, extruded
"Natural" or "black" color
Insulator, bearing, short runs of products that will be converted to injection molding
Ground
+.002/-.000
1.2 .75
Similar to nylon, better machinability
Delrin (acetal)
"Natural" or "black" color
Insulator, bearing
Ground
+.002/-.000
1.5 .7

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