TECHNICAL INFORMATION
Anasayfa / Technical Information / Free-machining steelsFREE-MACHINING STEELS
Free-Machining Steels are non-alloy steels containing high levels of Sulfur (S) and Manganese (Mn). Through Manganese-Sulfur (MnS) formed by Manganese and Sulfur, they are processed in fast machine tools (single or multi-spindle) working for mass production due to small and fragile chip formation. Cutting speeds are increased throgh Lead (Pb) added to these steels at a rate of 0.15-0.35%. Sometimes, instead of Lead (Pb), Tellurium (Te), Bismuth (Bi) and Selenium (Se) are also used for the same purpose. Higher Phosphorus (P) content than other steels improves chip brittleness and cutting surface quality. Since the surfaces that do not require machining should be within precise measurement tolerances, free-machining steels are mostly used as cold drawn. Meanwhile, steels containing about 0.12% sulfur and low carbon, called semi-automatic steel, are used in the manufacture of hot and cold forging and punching parts, as well as good machinability. Free-machining steels provide the following advantages in lathes that can produce fast and mass production.
- It provides high diamond bit life suitable for the processing speed of the machine.
- It provides good chip(spall) brittleness, which enables the workpieces to be processed easily and to move freely on the machine.
- It provides a good surface quality on the machined part due to its very low cutting forces.
- CHEMICAL ANALYZES
- COMPARISON TABLE
| CHEMICAL ANALYZES | ||||||||
|---|---|---|---|---|---|---|---|---|
| STEEL | CHEMICAL COMPOSITION (% Weight) | |||||||
| Kalite | C | Si | Mn | P | S | Pb | Te | Bi |
| NON ANNEALING LEADED FREE MACHINING STEELS | ||||||||
| 11 SMn 30 | 0,14 max | 0,05 max | 0,90 – 1,30 | 0,11 max | 0,27 – 0,33 | - | - | - |
| 11 SMnPb 30 | 0,14 max | 0,05 max | 0,90 – 1,30 | 0,11 max | 0,27 – 0,33 | 0,20 – 0,35 | - | - |
| 11 SMnPb 30+Te+Bi (TELBY) | 0,14 max | 0,05 max | 1,00 – 1,50 | 0,11 max | 0,27 – 0,33 | 0,20 – 0,35 | 0,01 – 0,05 | 0,05 – 0,09 |
| 11 SMn 37 | 0,14 max | 0,05 max | 1,00 – 1,50 | 0,11 max | 0,34 – 0,40 | - | - | - |
| 11 SMnPb 37 | 0,14 max | 0,05 max | 1,00 – 1,50 | 0,11 max | 0,34 – 0,40 | 0,20 – 0,35 | - | - |
| 11 SMnPb 37+Te (TELYX) | 0,14 max | 0,05 max | 1,00 – 1,50 | 0,11 max | 0,34 – 0,40 | 0,20 – 0,35 | 0,005 – 0,030 | - |
| 11 SMnPb 37+Te+Bi (TELBY PLUS) | 0,14 max | 0,05 max | 1,00 – 1,50 | 0,11 max | 0,34 – 0,40 | 0,20 – 0,35 | 0,01 – 0,05 | 0,05 – 0,09 |
| 28 SMnPb 28 (PR 60) | 0,25 – 0,30 | 0,30 max | 1,10 – 1,60 | 0,10 max | 0,24 – 0,32 | 0,15 – 0,30 | - | - |
| HEAT TREATED LEADED FREE MACHINING STEELS | ||||||||
| 10 S 20 | 0,07 – 0,13 | 0,40 max | 0,70 – 1,10 | 0,06 max | 0,15 – 0,20 | - | - | - |
| 10 SPb 20 | 0,07 – 0,13 | 0,40 max | 0,70 – 1,10 | 0,06 max | 0,15 – 0,20 | 0,20 – 0,35 | - | - |
| ANNEALING LEADED FREE MACHINING STEELS | ||||||||
| 35 S 20 | 0,32 – 0,39 | 0,40 max | 0,70 – 1,10 | 0,06 max | 0,15 – 0,25 | - | - | - |
| 35 SPb 20 | 0,32 – 0,39 | 0,40 max | 0,70 – 1,10 | 0,06 max | 0,15 – 0,25 | 0,15 – 0,35 | - | - |
| 36 SMn 14 | 0,32 – 0,39 | 0,40 max | 1,30 – 1,70 | 0,06 max | 0,10 – 0,18 | - | - | - |
| 36 SMnPb 14 | 0,32 – 0,39 | 0,40 max | 1,30 – 1,70 | 0,06 max | 0,10 – 0,18 | 0,15 – 0,35 | - | - |
| 38 SMn 28 +Te | 0,35 – 0,40 | 0,40 max | 1,20 – 1,50 | 0,06 max | 0,24 – 0,33 | - | 0,004 – 0,020 | - |
| 38 SMnPb 28 +Te | 0,35 – 0,40 | 0,40 max | 1,20 – 1,50 | 0,06 max | 0,24 – 0,33 | 0,15 – 0,35 | 0,01 – 0,05 | - |
| 44 SMn 28 | 0,40 – 0,48 | 0,40 max | 1,30 – 1,70 | 0,06 max | 0,24 – 0,33 | - | - | - |
| 44 SMnPb 28 | 0,40 – 0,48 | 0,40 max | 1,30 – 1,70 | 0,06 max | 0,24 – 0,33 | 0,15 – 0,35 | - | - |
| 46 S 20 | 0,42 – 0,50 | 0,40 max | 0,70 – 1,10 | 0,06 max | 0,15 – 0,25 | - | - | - |
| 46 SPb 20 | 0,42 – 0,50 | 0,40 max | 0,70 – 1,10 | 0,06 max | 0,15 – 0,25 | 0,15 -0,35 | - | - |
| COMPARISON TABLE | |||||
|---|---|---|---|---|---|
Quality EURONROM | ALMANYA (DIN) | AMERİKA (SAE) | İTALYA (UNI) | İNGİLTERE (BS) | FRANSA (AFNOR) |
| NON ANNEALING LEADED FREE MACHİNİNG STEELS | |||||
| 11 SMn 30 | 9 SMn 28 | 1213 | CF 9 SMn 28 | 230 M 07 | S 520 |
| 11 SMnPb 30 | 9 SMnPb 28 | 12 L 13 | CF 9 SMnPb 28 | 230 M 07 Pb | S 250 Pb |
| 11 SMnPb 30+Te+Bi | 9 SMnPb 28+Te+Bi | 12 L 13+Te+Bi | CF 9 SMnPb 28+Te+Bi | - | S 250 Pb+Te+Bi |
| 11 SMn 37 | 9 SMn 36 | 1214 | CF 9 SMn 36 | 230 M 07 | S 300 |
| 11 SMnPb 37 | 9 SMnPb 36 | 12 L 14 | CF 9 SMnPb 36 | 230 M 07 Pb | S 300 Pb |
| 11 SMnPb 37+Te | 9 SMnPb 28+Te | 12 L 13+Te | CF 9 SMnPb 28+Te | - | S 250 Pb+Te |
| 11 SMnPb 37+Te+Bi | 9 SMnPb 36+Te+Bi | 12 L 14+Te+Bi | CF 9 SMnPb 36+Te+Bi | - | S 300 Pb+Te+Bi |
| 28 SMnPb 28 | - | - | - | - | - |
| HEAT TREATED LEADED FREE MACHİNİNG STEELS | |||||
| 10 S 20 | 10 S 20 | 1109 | CF 10 S 20 | 210 M 15 | 13 MF 4 |
| 10 SPb 20 | 10 SPb 20 | 11 L 09 | CF 10 SPb 20 | - | 13 MF 4 Pb |
| ANNEALING LEADED FREE MACHİNİNG STEELS | |||||
| 35 S 20 | 35 S 20 | 1140 | - | 212 M 36 | - |
| 35 SPb 20 | 35 SPb 20 | 11 L 40 | - | 212 M 36 Pb | - |
| 36 SMn 14 | 36 SMnPb 14 | 11 L 37 | CF 35 SMnPb 10 | 216 M 36 | 35 MF 6 |
| 36 SMnPb 14 | 36 SMnPb 14 | 11 L 37 | CF 35 SMnPb 10 | 216 M 36 Pb | 35 MF 6 Pb |
| 38 SMn 28+Te | - | - | - | - | - |
| 38 SMnPb 28+Te | - | - | - | - | - |
| 44 SMn 28 | - | 1144 | CF 44 SMn 28 | 226 M 44 | 45 MF 6.3 |
| 44 SMnPb 28 | - | 11 L 44 | CF 44 SMnPb 28 | 226 M 44 Pb | 45 MF 6.3 Pb |
| 46 S 20 | 45 S 20 | 1146 | - | - | - |
| 46 SPb 20 | 60 S 20 | - | - | - | - |