This document discusses CBN/PCD tools for machining mill rolls. It provides information on: 1. Common types of mill rolls and their hardness levels. 2. Recommended CBN and PCD insert grades from Halnn for different roll materials, along with example cutting parameters. 3. Details on Halnn's CBN grades BN-K1, BN-S20, and BNK30 that are suited for cast iron, hardened steel, and cast iron rolls respectively. 4. The advantages of Halnn's solid CBN inserts for machining cast rolls and forged steel rolls.

1. To be No.1 in Superhard Tools Industry !
CBN/PCD Tools for Mill Rolls
Zhengzhou Halnn Superhard
Materials Co.Ltd
2017.11

2. Rolls Common Cutting Types

3. Common Rolls and Hardness
Graphite Semi-steel
Rolls
High Ni-Cr Cast
Iron Rolls
High Cr Cast Iron
Rolls
High Cr Cast Steel
Rolls
Semi-steel Roll
High-Carbon Semi-
steel Roll
HSD76~82
HSD72~78
HSD68~75
HSD60~68
HSD65~72
Alloy Cast Iron Rolls
Chilled Cast Steel
Rolls
HSS Roll
Forged Steel Cold
Roll
HSD62~68
HSD65~70
HSD55~62
HSD82~90
HSD92~105
Halnn remind:When turning rolls, the hardness is not the only standard to choose the
insert, the most important is the rolls materials and the chemical composition.

4. Rouhing Mill Rolls
High Ni-Cr Alloy Cast Iron Rolls
Materials:High Ni-Cr Cast Iron;
Hardness:HSD80;
Insert Model:BN-K1;
Cutting Data:
Vc=25m/min,ap=9mm,f=0.5mm/r
The efficiency will be 3 times
more than other carbide insert.

5. Finishing Mill Rolls
High Ni-Cr Alloy Cast Iron Rolls
Materials:High Ni-Cr Cast Iron；
Hardness:HSD63(HRC47)
Insert:BN-K1 or HLCBN；
Cutting Data:：
Vc=100m/min,ap=2mm,f=0.3mm/r
Insert Durability:About 100min

6. Semi-Finishing Mill Rolls
Chilled cast iron Roll
Materials:Chilled Cast Iron,
Hardness:HSD67(HRC50)
Insert:BN-K1
Cutting Data:Vc=66m/min,ap=2mm,
f=0.5mm/r
Efficiency:It will be 2 times more
than other carbide insert, and
durability will be more than 3 times.

7. Finishing Mill Rolls
Forged Steel Rolls
Materials:Forged Steel
Hardness:HRC60
Insert:BN-S20
Efficiency: It will be 5 times
more than carbide insert.

8. Turning Grooves of the Mill Roll
High Boron Steel Rolls
Halnn RCGX CBN
Materials:H
Hardness:HSD68
Insert:HLCBN
Cutting Data:
Vc=80m/minap=0.5mm,
f=0.3mm/r；
Efficiency：
Each Insert can
machining about 24
grooves.

9. Repair Thread Rolls
Repair thread rolls
Materials:High Speed Steel (HSS)
Hardness: HRC67
Insert:BN-S20 or BN-S10
Cutting Data:
Vc=68m/min,ap=0.5mm,f=0.5mm/r
Efficiency：It is 5 times more than
other carbide tools, the durability is
about 4 times.
BN-S10

10. Turning Tungsten Carbide Rings
Turning Tungsten Carbide Rings
Materials:WC(Tungesten Carbide）；
Hardness:HRA88
Insert:CDW20；
(For some shaped or large carbide
rings, hard turning is more efficient
than grinding）
Tungesten Carbide Rings

11. Other Rolls and PCD Insert

12. Solutions for Rolls
When machining Rolls, we need to know the following
details before make solutions:
1.Rolls Materials (Castings or Forged Steel) to make sure
the insert materials
2.Machining Type(Roughing or Finishing) to make sure
the insert Approximate size.
3. The tool holder, normally choosing the tool holder
depending on the “Length-Diameter”Ratio(L/D)
If L/D is big, you'd better choose 90 or 75 degree tool
holder, if L/D is small, you'd better choose 45 degree or
Circular turning tool.

13. Solutions for Rolls
Common Insert and the tool holder：
1.Machining Rolls Body：
Tool Holder: CRSNR/L
Insert:RNUN200800 RNMN160800 RNMN120400
Tool Holder:45 degree CSSNR/Lor75 degree CSRNR/L
Insert:SNMN150716,SNMN120712 or SNMN120412(08)
Tool Holder: 95 degree CCLNR/L
Insert:CNMN1207orCNMN1204
2. Turning Rolls Grooves:
Tool Holder:CRDCN4040(3232)
Insert:RCGX-V or RCGX-Y.

14. Cutting Parameters of Different Rolls
No. Rolls Materials Rolls Hardness
Recommend Halnn
Grade
Vc
(m/min)
ap
(mm)
Fr
(mm/r)
1
High Ni-Cr Cast Iron
Rolls
HSD72~82 BN-K1
15~30 3~7 1~2.5
20~40 4 1~2.5
2 High Cr Cast Iron Rolls HSD72~82 BN-K1
10~20 4 0.5~1.2
15~30 3~7 1.5~2.5
3 HSS Rolls HSD82~90
BN-S20/BN-
S10/BNK30
5~15 3~8 1.5~2.5
4 Cast Semi-Steel Rolls HSD55~65 BN-K1 30~60 4 1.5~2.5
5
High-Carbon Semi-steel
Roll
HSD65~72 BN-K1 25~50 4 1.5~2.5
6 Chilled Cast Iron Rolls HSD50~70 BN-K1 25~50 4 1.5~2.5
7 High Cr Steel Cast Rolls HSD68~75 BN-S20 20~45 4 1.5~2.5
8 Tungsten Carbide Ring HRA88 BN-S300/BNK30 10~15 1 0.5~1.2

15. Halnn CBN Grade for Rolls
ISO
Code
Insert
Grade
Suited Materials Advantages Image
K/S BN-K1
Chilled Cast Iron Good Collapse Resistance
Wear Resistant Cast Iron
Excellent Fracture Resistance
High Manganese Steel
H BN-S20
Hardened Steel Excellent Wear Resistance
Rolled Hardened Steel
Good Thermal Shock Resistance
Wear Resistant and Heat-resistant Steel
K BN-S300 Cast Iron Iron Series Good Keeness
H BN-S200
Hardened Steel
Excellent Abrasive Resistance
Superalloy
K BNK30 Cast Iron Excellent Abrasive Resistance

16. Halnn PCD Grade for reference
Insert
Grade
Process
Average
Size
Product Features Application Industry
CDW10
Ultra
Precision
2μm
High Surface Roughness,
Ultra precision
Suit for low silicion Aluminum
alloy, Copper alloy
CDW20Rough/Finish 10μm
Higher surface finish,
abrasion resistance and
impact resistance
Widely used for semi-content
silision aluminum alloy, Copper
alloy, ferrous metal and some
composites
CDW30 Roughing 25μm High abrasive resistance
Suit for abrasive resistant materials
and high content silicion aluminum
alloy

17. BN-K1 Solid CBN for Casting Rolls
Characters of Cast Rolls：
(1) High Hardness of the materials
(2) Casting Defects, such as stomach, sand,ect
Advantages of BN-K1：
(1) Excellent abrasive resistance
(2) Good Impact resistance
(3) Not easily Chipping
Suit for various casting rolls, such as chilled cast iron rolls,
High Chromium(Nickel) cast iron rolls .

18. BN-S20 Solid CBN for forged steel rolls
Suited Forged Steel Materials:
GCr15(100Cr6),Cr3,Cr5,Cr6,C12,9Cr2Mo,ect.
These rolls blank belong to forged steel component, and usually used for
chilled work rolls.
BN-S20: Researched specific for forged steel rolls
with Long iron scrap material, not only has as
good toughness as BN-K1, but also have excellent
abrasive resistance.

19. CBN/PCD Insert for Rolls
CDW20

20. Tool Holder

21. About Halnn
The predecessor of Halnn is Henan Superhard Material
Institute, we are the first R&D enterprise focusing on cutting
tools for gray cast iron, all kinds of wear resistant cast iron/cast
steel and hardened steel materials.
Our main products include PCBN Inserts, Solid CBN Insert, we
have obtained several practical patents, lead the world class
level, especially in interrupt cutting hardened steel, high speed
machining Hi-Cr white cast iron and other high hardness
materials industries.

22. To be No.1 in Superhard
Tools Industry !
Thank You !
Zhengzhou Halnn Superhard
Materials Co.,Ltd
2017,11
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