STRESSPROOF®
Stressproof rounds offer a combination of high strength and excellent machinability. They are produced by a patented process which entails drawing the bar through a special die under heavy draft, then stress relieving it in a precisely controlled furnace. The resulting bar offers strength without heat treating, wearability without case hardening and outstanding machinability and tool life. Stressproof is produced from AISI 1144 carbon steel. Although Stressproof is certified to ASTM A311, it offers additional quality features not included in this spec. Examples are seam depth specification, warpage testing and machining testing which are all intregal parts of the quality assurance program. Stressproof is often used for parts requiring mechanical properties obtained by heat treating to a hardness range of 23-30 Rockwell C (Rc) after machining. The machinability rating is 83 % of 1212 screw stock with an average surface cutting speed of 140 feet per minute. Because Stressproof is a resulfurized steel, welding is not recommended.

STRESSPROOF is a registered trademark of the Niagara Lasalle Corporation.


CHEMICAL ANALYSIS
Carbon Manganese Phosphorus Sulphur Silicon
.40/.48 1.35/1.65 .040 max 24/.33 .35 max

MECHANICAL PROPERTIES
(The following values are average and should be considered as representative of the grade.)
Tensile
Strength
(PSI)		 Yield
Strength
(PSI)		 Elongation Reduction
of area		 Typical
RockwellC
Hardness
115,000 min 100,000 min 8% min
(7% min above 3")		 25% min
(20% min above 2")		 25

Size Range is 1/4" dia thru 4 1/2" dia. Stock lengths are 12 ft. long, also available cut to size...

DIAMETER TOLERANCES
Size range in inches + 0Minus in Inches
1/4" to 1 1/2" incl. 0.004"
Over 1 1/2" to 2 1/2" incl. 0.005"
Over 2 1/2" to 4" incl. 0.006"
Over 4 to 4 1/2" incl. 0.007"