(!)NOTE : Windows 7 users won’t be able to use some latest features of eCatalog/WOS since Microsoft is ending support for Windows 7 on 14 Jan, 2020. Please upgrade your system for uninterrupted services.
- Scheduled Maintenance Notice: This site will be unavailable due to scheduled maintenance from 4:30 2/3 to 3:30 (IST) 3/3/2025. We apologize for the inconvenience.
- Notice of End of Sales for Economy Series Pneumatic Equipment Category. More information.
Ball End Mills (Carbide)（R Precision：±0.005）
Brand |
|
|---|---|
| CAD |
|
| Days to Ship |
|
10 items
- Sort By
-
You can add up to 6 items per a category to the compare list.
Ball End Type, 2-Flute WXL-EBD
OSG
[Features]
· High-accuracy ball end mill coated with WXL hard lubricating film coating.
Proven performance on a wide range of work materials.
Long life regardless of whether being used for dry-type or wet-type machining.R Size(mm) Blade length (ℓ)(mm) Underneck length (ℓ1)(mm) Shank diameter (d)(mm) Number of flutes(sheet) Overall Length (L)(mm) work material R Precision(μm) Machining Application Coating Type 0.05 ～ 2.75 0.2 ～ 12 - 4 ～ 6 2 40 ～ 80 general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[◎] / Cast Iron[◎] / Aluminum[○] / Titanium[○] / Copper[◎] ±0.005 Curved surface / Side / Engraving / R Groove For General Steels (AlCrN, etc.) Ball From: ₹ 3,011.00 Days to Ship: 5 Day(s) or more 
5 Day(s) or more
-
You can add up to 6 items per a category to the compare list.
MISUMI
CBN ball end mill that's ideal for precision finishing is available at a value price
- High-Hardness Steel
- 2 Flutes
R Size(mm) Blade length (ℓ)(mm) Underneck length (ℓ1)(mm) Shank diameter (d)(mm) Number of flutes(sheet) Overall Length (L)(mm) work material R Precision(μm) Machining Application Coating Type 0.3 ～ 1 0.5 ～ 1.2 1.5 ～ 5 4 2 50 general steel[○] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[◎] / High Hardness Steel-HRC60[◎] / High Hardness Steel-HRC65[◎] ±0.005 Curved surface / Side / Engraving / R Groove Non-Coated Ball From: ₹ 10,797.96 Days to Ship: 6 Day(s) or more
6 Day(s) or more
-
You can add up to 6 items per a category to the compare list.
TSC series carbide ball end mill, regular model
MISUMI
[Features]
·Regular bridge length allows for many regrinding times
·Can be regrinded. Please refer to the page dedicated to "regrinding service" for usage procedures, range of services, prices, etc.- TS
- General Steel
- 2 Flutes
- R (Regular)
R Size(mm) Blade length (ℓ)(mm) Underneck length (ℓ1)(mm) Shank diameter (d)(mm) Number of flutes(sheet) Overall Length (L)(mm) work material R Precision(μm) Machining Application Coating Type 0.2 ～ 2.5 1.5 ～ 12 - 4 ～ 6 2 50 ～ 80 general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[○] / Aluminum[○] / Copper[○] ±0.005 Curved surface / Side / Engraving / R Groove For High Hardness (Silicon Group) Ball From: ₹ 1,211.55 Days to Ship: 6 Day(s) or more
6 Day(s) or more
-
You can add up to 6 items per a category to the compare list.
TSC series carbide ball end mill, for shrinkage fitting, 2-flute / stub model
MISUMI
[Features]
·Compatible with shrink fit chucks for high-precision machining
·Designed with short flute length and overall length for shrink fit and emphasis on rigidity
It has coating with high oxidation resistance and high hardness, and achieves a long service lifespan. Effective in high-speed machining and dry machining as coating properties- TS
- General Steel
- 2 Flutes
- B (Stub)
R Size(mm) Blade length (ℓ)(mm) Underneck length (ℓ1)(mm) Shank diameter (d)(mm) Number of flutes(sheet) Overall Length (L)(mm) work material R Precision(μm) Machining Application Coating Type 0.2 ～ 2.5 0.4 ～ 5 - 4 ～ 6 2 40 general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[○] / Aluminum[○] / Copper[○] ±0.005 Curved surface / Side / Engraving / R Groove For High Hardness (Silicon Group) Ball From: ₹ 1,397.93 Days to Ship: 6 Day(s) or more
6 Day(s) or more
-
You can add up to 6 items per a category to the compare list.
XAL series carbide ball end mill, 2-flute / short model
MISUMI
XAL Series is the definitive choice for cost-sensitive customers
- Volume Discount
- XAL
- General Steel
- 2 Flutes
R Size(mm) Blade length (ℓ)(mm) Underneck length (ℓ1)(mm) Shank diameter (d)(mm) Number of flutes(sheet) Overall Length (L)(mm) work material R Precision(μm) Machining Application Coating Type 0.05 ～ 2.75 0.2 ～ 12 - 3 ～ 6 2 40 ～ 80 general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[◎] / Aluminum[◎] / Copper[◎] / Resin[○] ±0.005 Curved surface / Side / Engraving / R Groove For General Steels (AlCrN, etc.) Ball From: ₹ 907.20 Days to Ship: 6 Day(s) or more
6 Day(s) or more
-
You can add up to 6 items per a category to the compare list.
TSC Series Carbide Ball End Mill 2-Flute / Short Type
MISUMI
[Features]
·Good finish can be expected for surface coarse of workpiece after processing
It has coating with high oxidation resistance and high hardness, and achieves a long service lifespan. Effective in high-speed machining and dry machining as coating properties
·Can be regrinded. Please refer to the page dedicated to "regrinding service" for usage procedures, range of services, prices, etc.- TS
- General Steel
- 2 Flutes
- S (Short)
R Size(mm) Blade length (ℓ)(mm) Underneck length (ℓ1)(mm) Shank diameter (d)(mm) Number of flutes(sheet) Overall Length (L)(mm) work material R Precision(μm) Machining Application Coating Type 0.05 ～ 2.75 0.2 ～ 8 - 3 ～ 6 2 40 ～ 60 general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[○] / Aluminum[○] / Copper[○] ±0.005 Curved surface / Side / Engraving / R Groove For High Hardness (Silicon Group) Ball From: ₹ 1,184.00 Days to Ship: 6 Day(s) or more
6 Day(s) or more
-
You can add up to 6 items per a category to the compare list.
TSC series carbide ball end mill, 2-flute / short, long shank model
MISUMI
[Features]
·Long shank type ideal for deep cavity milling
It has coating with high oxidation resistance and high hardness, and achieves a long service lifespan. Effective in high-speed machining and dry machining as coating properties
·Can be regrinded. Please refer to the page dedicated to "regrinding service" for usage procedures, range of services, prices, etc.- TS
- General Steel
- 2 Flutes
- S (Short)
R Size(mm) Blade length (ℓ)(mm) Underneck length (ℓ1)(mm) Shank diameter (d)(mm) Number of flutes(sheet) Overall Length (L)(mm) work material R Precision(μm) Machining Application Coating Type 0.5 ～ 2.5 2 ～ 8 - 3 ～ 6 2 70 ～ 100 general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[○] / Aluminum[○] / Copper[○] ±0.005 Curved surface / Side / Engraving / R Groove For High Hardness (Silicon Group) Ball From: ₹ 3,523.93 Days to Ship: 6 Day(s) or more
6 Day(s) or more
-
You can add up to 6 items per a category to the compare list.
MRC Series Carbide Ball End Mill, for Heat-Treated Steel Machining, 2-Flute / Short Model
MISUMI
High-performance products with emphasis on the machined surface accuracy are available in the deferred prices of the conventional products!
- MR
- General Steel
- 2 Flutes
- S (Short)
R Size(mm) Blade length (ℓ)(mm) Underneck length (ℓ1)(mm) Shank diameter (d)(mm) Number of flutes(sheet) Overall Length (L)(mm) work material R Precision(μm) Machining Application Coating Type 0.1 ～ 6 0.4 ～ 15 - 4 ～ 12 2 50 ～ 110 general steel[○] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[◎] / High Hardness Steel-HRC60[○] / High Hardness Steel-HRC65[○] / Stainless Steel[○] / Cast Iron[◎] ±0.005 Curved surface / Side / Engraving / R Groove MRC Ball From: ₹ 1,074.55 Days to Ship: 6 Day(s) or more
6 Day(s) or more
-
You can add up to 6 items per a category to the compare list.
MRC Series Carbide Ball End Mill, for Heat-Treated Steel Machining, 2-Flute / Regular Model
MISUMI
The user friendly regular flute length type is released simultaneously
- MR
- General Steel
- 2 Flutes
- R (Regular)
R Size(mm) Blade length (ℓ)(mm) Underneck length (ℓ1)(mm) Shank diameter (d)(mm) Number of flutes(sheet) Overall Length (L)(mm) work material R Precision(μm) Machining Application Coating Type 0.2 ～ 6 1.5 ～ 22 - 4 ～ 12 2 50 ～ 110 general steel[○] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[◎] / High Hardness Steel-HRC60[○] / High Hardness Steel-HRC65[○] / Stainless Steel[○] / Cast Iron[◎] ±0.005 Curved surface / Side / Engraving / R Groove MRC Ball From: ₹ 1,254.00 Days to Ship: 6 Day(s) or more
6 Day(s) or more
-
You can add up to 6 items per a category to the compare list.
XAL Series Carbide Ball End Mill, 2-Flute / Regular Model
MISUMI
The regular flute length type is introduced in the low-price and popular XAL balls
- XAL
- General Steel
- 2 Flutes
R Size(mm) Blade length (ℓ)(mm) Underneck length (ℓ1)(mm) Shank diameter (d)(mm) Number of flutes(sheet) Overall Length (L)(mm) work material R Precision(μm) Machining Application Coating Type 0.2 ～ 2.5 1.5 ～ 15 - 4 ～ 6 2 50 ～ 80 general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[◎] / Aluminum[◎] / Copper[◎] / Resin[○] ±0.005 Curved surface / Side / Engraving / R Groove For General Steels (AlCrN, etc.) Ball From: ₹ 1,044.13 Days to Ship: 6 Day(s) or more
6 Day(s) or more
| Brand |
|---|
| Product Series |
| From |
| Days to Ship |
| Specifications |
| R Size(mm) |
| Blade length (ℓ)(mm) |
| Underneck length (ℓ1)(mm) |
| Shank diameter (d)(mm) |
| Number of flutes(sheet) |
| Overall Length (L)(mm) |
| work material |
| R Precision(μm) |
| Machining Application |
| Coating |
| Type |
You can add up to 6 items per a category to the compare list.  | You can add up to 6 items per a category to the compare list.  | You can add up to 6 items per a category to the compare list.  | You can add up to 6 items per a category to the compare list.  | You can add up to 6 items per a category to the compare list.  | You can add up to 6 items per a category to the compare list.  | You can add up to 6 items per a category to the compare list.    | You can add up to 6 items per a category to the compare list.  | You can add up to 6 items per a category to the compare list.  | You can add up to 6 items per a category to the compare list.  | |
| Brand | OSG | MISUMI | MISUMI | MISUMI | MISUMI | MISUMI | MISUMI | MISUMI | MISUMI | MISUMI |
| Product Series | TSC series carbide ball end mill, for shrinkage fitting, 2-flute / stub model | TSC series carbide ball end mill, 2-flute / short, long shank model | MRC Series Carbide Ball End Mill, for Heat-Treated Steel Machining, 2-Flute / Short Model | MRC Series Carbide Ball End Mill, for Heat-Treated Steel Machining, 2-Flute / Regular Model | ||||||
| From | ₹ 3,011.00 | ₹ 10,797.96 | ₹ 1,211.55 | ₹ 1,397.93 | ₹ 907.20 | ₹ 1,184.00 | ₹ 3,523.93 | ₹ 1,074.55 | ₹ 1,254.00 | ₹ 1,044.13 |
| Days to Ship | 5 Day(s) or more | 6 Day(s) or more | 6 Day(s) or more | 6 Day(s) or more | 6 Day(s) or more | 6 Day(s) or more | 6 Day(s) or more | 6 Day(s) or more | 6 Day(s) or more | 6 Day(s) or more |
| Specifications |
|
|
|
|
|
|
|
|
| |
| R Size(mm) | 0.05 ～ 2.75 | 0.3 ～ 1 | 0.2 ～ 2.5 | 0.2 ～ 2.5 | 0.05 ～ 2.75 | 0.05 ～ 2.75 | 0.5 ～ 2.5 | 0.1 ～ 6 | 0.2 ～ 6 | 0.2 ～ 2.5 |
| Blade length (ℓ)(mm) | 0.2 ～ 12 | 0.5 ～ 1.2 | 1.5 ～ 12 | 0.4 ～ 5 | 0.2 ～ 12 | 0.2 ～ 8 | 2 ～ 8 | 0.4 ～ 15 | 1.5 ～ 22 | 1.5 ～ 15 |
| Underneck length (ℓ1)(mm) | - | 1.5 ～ 5 | - | - | - | - | - | - | - | - |
| Shank diameter (d)(mm) | 4 ～ 6 | 4 | 4 ～ 6 | 4 ～ 6 | 3 ～ 6 | 3 ～ 6 | 3 ～ 6 | 4 ～ 12 | 4 ～ 12 | 4 ～ 6 |
| Number of flutes(sheet) | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
| Overall Length (L)(mm) | 40 ～ 80 | 50 | 50 ～ 80 | 40 | 40 ～ 80 | 40 ～ 60 | 70 ～ 100 | 50 ～ 110 | 50 ～ 110 | 50 ～ 80 |
| work material | general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[◎] / Cast Iron[◎] / Aluminum[○] / Titanium[○] / Copper[◎] | general steel[○] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[◎] / High Hardness Steel-HRC60[◎] / High Hardness Steel-HRC65[◎] | general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[○] / Aluminum[○] / Copper[○] | general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[○] / Aluminum[○] / Copper[○] | general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[◎] / Aluminum[◎] / Copper[◎] / Resin[○] | general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[○] / Aluminum[○] / Copper[○] | general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[○] / Aluminum[○] / Copper[○] | general steel[○] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[◎] / High Hardness Steel-HRC60[○] / High Hardness Steel-HRC65[○] / Stainless Steel[○] / Cast Iron[◎] | general steel[○] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[◎] / High Hardness Steel-HRC60[○] / High Hardness Steel-HRC65[○] / Stainless Steel[○] / Cast Iron[◎] | general steel[◎] / Quenched and tempered steel[◎] / High Hardness Steel-HRC55[○] / Stainless Steel[○] / Cast Iron[◎] / Aluminum[◎] / Copper[◎] / Resin[○] |
| R Precision(μm) | ±0.005 | ±0.005 | ±0.005 | ±0.005 | ±0.005 | ±0.005 | ±0.005 | ±0.005 | ±0.005 | ±0.005 |
| Machining Application | Curved surface / Side / Engraving / R Groove | Curved surface / Side / Engraving / R Groove | Curved surface / Side / Engraving / R Groove | Curved surface / Side / Engraving / R Groove | Curved surface / Side / Engraving / R Groove | Curved surface / Side / Engraving / R Groove | Curved surface / Side / Engraving / R Groove | Curved surface / Side / Engraving / R Groove | Curved surface / Side / Engraving / R Groove | Curved surface / Side / Engraving / R Groove |
| Coating | For General Steels (AlCrN, etc.) | Non-Coated | For High Hardness (Silicon Group) | For High Hardness (Silicon Group) | For General Steels (AlCrN, etc.) | For High Hardness (Silicon Group) | For High Hardness (Silicon Group) | MRC | MRC | For General Steels (AlCrN, etc.) |
| Type | Ball | Ball | Ball | Ball | Ball | Ball | Ball | Ball | Ball | Ball |
Loading...
Configure
Specification/Dimensions
-
R Size(mm)
- 0.005
- 0.01
- 0.015
- 0.02
- 0.025
- 0.03
- 0.04
- 0.05
- 0.075
- 0.1
- 0.125
- 0.15
- 0.175
- 0.2
- 0.225
- 0.25
- 0.275
- 0.3
- 0.325
- 0.35
- R0.35
- 0.375
- 0.4
- R0.4
- 0.425
- 0.45
- R0.45
- 0.475
- 0.5
- 0.55
- 0.6
- R0.6
- 0.65
- 0.7
- 0.75
- R0.75
- 0.8
- 0.85
- 0.9
- 0.95
- 1
- 1.05
- 1.1
- 1.15
- 1.2
- 1.25
- R1.25
- 1.3
- 1.35
- 1.4
- 1.45
- 1.5
- R1.5
- 1.55
- 1.6
- 1.65
- 1.7
- 1.75
- R1.75
- 1.8
- 1.85
- 1.9
- 1.95
- 2
- R2
- 2.05
- 2.1
- 2.15
- 2.2
- 2.25
- R2.25
- 2.3
- 2.35
- 2.4
- 2.45
- 2.5
- 2.55
- 2.6
- 2.65
- 2.7
- 2.75
- R2.75
- 2.8
- 2.85
- 2.9
- 2.95
- 3
- R 3.0
- 3.05
- 3.1
- 3.15
- 3.175
- 3.2
- 3.25
- R3.25
- 3.3
- 3.35
- 3.4
- 3.45
- 3.5
- R3.5
- 3.55
- 3.6
- 3.65
- 3.7
- 3.75
- 3.8
- 3.85
- 3.9
- 3.95
- 4
- 4.05
- 4.1
- 4.15
- 4.2
- 4.25
- 4.3
- 4.35
- 4.4
- 4.45
- 4.5
- R4.5
- 4.55
- 4.6
- 4.65
- 4.7
- 4.75
- 4.8
- 4.85
- 4.9
- 4.95
- 5
- 5.05
- 5.1
- 5.15
- 5.2
- 5.25
- 5.3
- 5.35
- 5.4
- 5.45
- 5.5
- 5.55
- 5.6
- 5.65
- 5.7
- 5.75
- 5.8
- 5.85
- 5.9
- 5.95
- 6
- 6.05
- 6.1
- 6.15
- 6.2
- 6.25
- 6.3
- 6.35
- 6.4
- 6.45
- 6.5
- 6.55
- 6.6
- 6.65
- 6.7
- 6.75
- 6.8
- 6.85
- 6.9
- 6.95
- 7
- R7
- 7.05
- 7.1
- 7.15
- 7.2
- 7.25
- 7.3
- 7.35
- 7.4
- 7.45
- 7.5
- 7.55
- 7.6
- 7.65
- 7.7
- 7.75
- 7.8
- 7.85
- 7.9
- 7.95
- 8
- R8
- 8.05
- 8.1
- 8.15
- 8.2
- 8.25
- 8.3
- 8.35
- 8.4
- 8.45
- 8.5
- 8.55
- 8.6
- 8.65
- 8.7
- 8.75
- 8.8
- 8.85
- 8.9
- 8.95
- 9
- R9
- 9..5
- 9.05
- 9.1
- 9.15
- 9.2
- 9.25
- 9.3
- 9.35
- 9.4
- 9.45
- 9.5
- 9.55
- 9.6
- 9.65
- 9.7
- 9.75
- 9.8
- 9.85
- 9.9
- 9.95
- 10
- R10
- 10.25
- 10.5
- 10.75
- 11
- 11.5
- 12
- 12.25
- 12.5
- 12.75
- 13
- 13.5
- 14
- 14.5
- 15
- 15.5
- 16
- 16.5
- 17
- 17.5
- 18
- 18.5
- 19
- 19.5
- 20
- 22.0
- 22.5
- 23.0
- 24.0
- 25
-
Blade length (ℓ)(mm)
-
0.01～0.95
- 0.01
- 0.02
- 0.03
- 0.04
- 0.05
- 0.06
- 0.08
- 0.1
- 0.15
- 0.16
- 0.2
- 0.23
- 0.24
- 0.3
- 0.38
- 0.4
- 0.45
- 0.49
- 0.5
- 0.56
- 0.6
- 0.63
- 0.7
- 0.75
- 0.76
- 0.8
- 0.84
- 0.9
- 0.95
-
1～1.8
- 1
- 1.05
- 1.1
- 1.2
- 1.25
- 1.26
- 1.3
- 1.4
- 1.5
- 1.6
- 1.7
- 1.75
- 1.8
-
2～2.9
- 2
- 2.1
- 2.2
- 2.25
- 2.3
- 2.4
- 2.5
- 2.6
- 2.7
- 2.75
- 2.8
- 2.9
-
3～3.9
- 3
- 3.2
- 3.25
- 3.5
- 3.6
- 3.75
- 3.8
- 3.9
-
4～4.9
- 4
- 4.1
- 4.2
- 4.25
- 4.4
- 4.5
- 4.7
- 4.75
- 4.8
- 4.9
-
5～5.9
- 5
- 5.1
- 5.2
- 5.3
- 5.4
- 5.5
- 5.6
- 5.7
- 5.8
- 5.9
-
6～6.9
- 6
- 6.2
- 6.25
- 6.3
- 6.5
- 6.6
- 6.7
- 6.8
- 6.9
-
7～7.5
- 7
- 7.1
- 7.2
- 7.4
- 7.5
-
8～8.9
- 8
- 8.1
- 8.3
- 8.4
- 8.5
- 8.6
- 8.7
- 8.9
-
9～9.5
- 9
- 9.5
-
10～10.5
- 10
- 10.5
-
11～11.5
- 11
- 11.5
-
12～12.5
- 12
- 12.5
-
13～13.5
- 13
- 13.5
-
14～14.5
- 14
- 14.5
-
15
-
16～16.5
- 16
- 16.5
-
17
-
18
-
19
-
20
-
22
-
23
-
24
-
25
-
26
-
28
-
29
-
30
-
32
-
34
-
35
-
36
-
38
-
40
-
45
-
48
-
50
-
55
-
58
-
60
-
65
-
70
-
80
-
90
-
100
-
110
-
120
-
130
-
-
Underneck length (ℓ1)(mm)
-
Shank diameter (d)(mm)
-
Number of flutes(sheet)
-
Overall Length (L)(mm)
-
work material
-
R Precision(μm)
-
Machining Application
-
Coating
-
Type
- Ball
- Tapered neck ball
- Spherical Ball
Related Categories to Ball End Mills (Carbide)
Payment Method
- Credit Card
-
- Debit Cart
-
- Net Banking
-
- UPI
-
- Cheque on delivery
-
- Online payment
-
Social Media
MISUMI India Contact
Copyright © MISUMI Corporation All Rights Reserved.
How can we improve?
How can we improve?
Thank you for your time.
Your feedback is essential for our continuous improvement
Privacy Policy
Thank you for your cooperation.
Thank you for your time.
Your feedback is essential for our continuous improvement
Please use the inquiry form.
Privacy Policy