Solid CBN Inserts SNMN15/CNMN12 Heavy-Duty Machining High Manganese
Steel
1. Halnn CBN Grade BN-S20 for machining high manganese steel
| BN-S20 | Hardened Steel, Heat and abrasive resistant steel, High manganese
steel | Roughing,Semi-Finishing | HSS Rolls, Ball Screw, Wind Power Bearings, Crushing Cone |    |
2. About High Manganese Steel
Normally CBN only works when the steel component is hardened, with
a hardness above 50 HRC. One exception are the so called austenitic
high manganese steels. These are steels with a manganese content of
11% or more, originally invented by Sir Robert Hadfield. In its
original state, the material is usually around 250 HB, but the
hardness is increased significantly through deformation hardening
when used, without any loss of toughness. The hardness is also very
difficult to measure with high accuracy due to the high level of
work hardening.
The application areas for these materials are in the mining
industry, such as in components for cement mixers, rock crushers,
railway switches and crossings, crawler treads for tractors, teeth
for excavators and other high impact and abrasive environments,the
typical component is crushing cone.
3.CBN Insert Replace Carbide Insert Application
When using carbide has to be very low, cutting speeds in the range
of 20 to 30 m/min is normal. By instead using CBN, cutting speeds
can be increase to 200 m/min, which significantly improves
productivity.
One typical application where Halnn Tools has a long experience and
has been very successful is turning of crushing cones.
| BN-S20 Solid CBN Inserts machining high manganese steel |
| Materials | High Manganese Steel |
| Selected insert | BN-S20 SNMN120716 |
| Cutting Condition | ap=7.5mm,Fr=0.5mm/r,Vc=65m/min |
| Testing Performance |
| Insert Materials | Cutting Speed Vc | Cutting Depth ap | Too life/Edge |
| Halnn BN-S20 | 65m/min | 7.5mm | 2 pcs |
| Carbide Insert | 19m/min | 3.5mm | 0.5 pcs |
4. Common Models SNMN/CNMN Solid CBN Inserts Specification for
machining high manganese Steel
SNMN/SNGN Solid CBN Inserts 
|
| Type | Dimension |
Standard Chamfer | Grades | Corresponding tool holder |
| L(mm) | φI.C(mm) | S(mm) | r(mm) | BN-S20 |
| SNMN120404 | 12 | 12.7 | 4.76 | 0.4 | S01020 S01025 S02020 S02030 S05020 S10020 | ● | CSDNN CSSNR/L CSKNR/L CSRNR/L CSXNR/L S25T-CSKNR/L |
| SNMN120408 | 12 | 12.7 | 4.76 | 0.8 | ● |
| SNMN120412 | 12 | 12.7 | 4.76 | 1.2 | ● |
| SNMN120712 | 12 | 12.7 | 7.94 | 1.2 | ● |
| SNMN120716 | 12 | 12.7 | 7.94 | 1.6 | ● |
| SNMN150716 | 15 | 15.875 | 7.94 | 1.6 | ● |
| SNMN201020 | 20 | 20 | 10 | 2.0 | ● |
CNMN/CNGN Solid CBN Inserts 
|
| Type | Dimension | Standard Chamfer | Grades | Corresponding tool holder |
| L(mm) | φI.C(mm) | S(mm) | r(mm) | BN-S20 |
| CNMN120404 | 12 | 12.7 | 4.76 | 0.4 | S01020 S01025 S02020 S02030 S02530 S03020 | ● | CCLNR/L S25T-CCLNR/L |
| CNMN120408 | 12 | 12.7 | 4.76 | 0.8 | ● |
| CNMN120412 | 12 | 12.7 | 4.76 | 1.2 | ● |
| CNMN120416 | 12 | 12.7 | 4.76 | 1.6 | ● |
| CNMN120704 | 12 | 12.7 | 7.94 | 0.4 | ● |
| CNMN120708 | 12 | 12.7 | 7.94 | 0.8 | ● |
| CNMN120712 | 12 | 12.7 | 7.94 | 1.2 | ● |
| CNMN120716 | 12 | 12.7 | 7.94 | 1.6 | ● |
5. Typical Application of Machining High Manganese Steel
