ACH-12-L
Accuhold End Mill Ultra Precision Extension Holder
Accuhold Extension Holder 0.375in ID, 0.75in Shank, 6in OAL, 5/16-24 Screw
OrderingACH-12-L·Uncoated·$384.55
Accuhold ultra-precision end mill extension holders — +.00015"/-0 hole tolerance to eliminate runout and tool breakage.
- Hole diameter tolerance +.00015"/-.00000 — the tightest-tolerance end mill extension, made to eliminate runout (TIR) and reduce tool breakage
- Reaches into deep parts: standard lengths 2-1/8" to 6-1/2" including -L long versions (ACH-04-L, ACH-06-L, ACH-08-L, ACH-12-L, ACH-16-32-L)
- Inch ACH line holds 3/32" to 1" tool shanks on 3/8" to 1-1/4" holder shanks
- ACH-M metric-to-inch line holds 3mm to 25mm tool shanks on inch holder shanks — converts an inch tool holder to metric tooling
- MAH all-metric line: 3-12mm holes on 10-25mm shanks, 82.5-150mm OAL
- Set screw sizes from 5-40 up to 7/16-20 matched to each holder
- Large sizes use stepped heads: ACH-16/M12 have a 1" dia x 1.5" head; ACH-24/32 and ACH-M18/M25 have 1-1/4" dia x 2-1/4" heads with 2" hole depth
- Shank tolerance -.0001/-.0003, OAL +/-.060
From the RobbJack Applications Guide.
About this series
ACH Accuhold End Mill Ultra Precision Extension Holders
The tightest-tolerance end mill extension to eliminate runout
The ACH Accuhold is an ultra precision end mill extension holder used to reach into parts that need longer length. Precision end mills need precision holders to eliminate runout (TIR) and reduce tool breakage. Inch hole sizes range from 3/32" to 1", with overall lengths from 2-1/8" up to 6" and matching set screws.
- Ultra precision extension holder
- Eliminates runout (TIR) and reduces tool breakage
- Hole Dia. tolerance +.00015/-.00000
- Shank Dia. tolerance -.0001/-.0003
- OAL tolerance +/-.060
Holds inch-shank end mills; the largest holders (ACH-24 and ACH-32) have a 1-1/4" diameter x 2-1/4" long head with a hole depth of only 2" deep
Headline spec
Inch hole diameters 3/32"-1"; overall lengths 2-1/8" to 6"
Best for
- Reaching into parts that need longer length
- Extending precision end mills while maintaining low runout
Specifications
US machining terms with ISO 13399 codes.
- Holder DiameterDMM
- 0.75″
- Accessory Type
- Extension Holder
- Overall Length (OAL)OAL
- 6″
- Series
- ACH — Accuhold End Mill Ultra Precision Extension Holder
See it run
Tolerances
| Type | Min | Max |
|---|---|---|
| Hole Diameter | 0 | +0.00015 |
| Overall Length | -0.06 | +0.06 |
| Shank Diameter | -0.0001 | -0.0003 |
Choose the finish(1 option)
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Part ACH-12-L
Made & shipped in the USA · lead time confirmed at order. Test this tool in your spindle at retail, or get it through your RobbJack distributor.
Performance guaranteed. Run it against the tool you use today — if it doesn't beat it, we'll make it right.
Uncoated
$384.55
ACH-12-L
More in the ACH series
Same series, different size — what changes from this tool is shown in red.