Bethlehem Lukens Plate
Free Machining Steels
 

Table 1

Bethlehem Free-Machining Steels
Fast-Cut™ Carbon Steels

Chemistry*
         C Mn P S Si
Fast-Cut 20 .14 / .22 1.00 / 1.30 .040 max. .24 / .33 .10 / .40
Fast-Cut 45 .45 / .50 1.00 / .1.30 .040 max. .24 / .33 .10 / .40
Clean-Cut� Carbon Steels

Chemistry**
      C Mn P S Si
Clean-Cut 20 .14 / .22 1.20 / .1.50 .040 max. .06 / .12 .10 / .40
Clean-Cut 45 .42 / .50 1.20 / .1.50 .040 max. .06 / .12 .10 / .40
Clean-Cut� Alloy Steels
Available Chemistries with Sulfur of .02 / .04%* AISI 4140, 4142, 4150, 8620, MTD� #1, #2, and
#4.*
*Weight Percent by Heat Analysis **Clean-Cut Steels Are Also Calcium Treated
The sulfur content is critical to performance during machining. The reproducibility of the sulfur contents in all three Bethlehem families of free-machining steels is demonstrated in Figure 3.   Because of the different sulfur levels in these three families of steels, the sulfide inclusion structure and, thus, machining characteristics are also different. Comparisons of the sulfide inclusion structures are shown in Figure 4.
 

Bethlehem Lukens Plate Products

If you have any questions or comments, please Contact Us
�1999, Bethlehem Steel Corporation