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AccessoriesMade in USA

ACH-M14

Metric to Inch End Mill Ultra Precision Extension Holder, Inch Shank

Metric Accuhold Extension Holder 14mm ID, 1.000in Shank, 5.50in OAL, 3/8-24 Screw

Metric to Inch End Mill Ultra Precision Extension Holder, Inch Shank — ACH-M14
Series photo — representative of the ACH-M family
ACH extension holder dimension diagram showing overall length, shank diameter and hole diameter for straight and stepped-head styles
Dimension reference — labels match the specifications below
Speeds & FeedsDialed to this exact tool — free
RobbJack ACH Accuhold ultra precision end mill extension holder with set screws

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-M Metric-to-Inch End Mill Ultra Precision Extension Holders

Convert your inch tool holder to hold metric shanks

The ACH-M is a metric end mill extension holder with an inch shank. Use this precision end mill extension holder to convert your inch tool holder to be able to hold onto metric shanks. It is the tightest tolerance end mill extension, used to reach into parts that need longer length; precision end mills need precision holders to eliminate runout (TIR) and reduce tool breakage. Metric hole sizes range from 3 mm to 25 mm with inch shanks.

  • Metric end mill extension holder with inch shank
  • Converts an inch tool holder to hold metric shanks
  • Tightest tolerance end mill extension
  • Eliminates runout (TIR) and reduces tool breakage
  • Hole Dia. tolerance +.004/-.000 mm
  • Shank Dia. tolerance +.000/-.007 mm
  • OAL tolerance +/-1.5 mm

Converts inch tool holders to metric shanks; ACH-M12 has a 1" diameter x 1.5" long head, and ACH-M18 and ACH-M25 have a 1-1/4" diameter x 2-1/4" long head with a hole depth of only 2" deep

Headline spec

Metric hole diameters 3 mm-25 mm; inch shanks 3/8" to 1-1/4"; 3-1/4" to 6-1/2" OAL

Best for

  • Converting an inch tool holder to hold metric-shank end mills
  • Reaching into parts that need longer length

Specifications

US machining terms with ISO 13399 codes.

Holder DiameterDMM
1″
Accessory Type
Extension Holder
Overall Length (OAL)OAL
5.5″
Series
ACH-M — Metric to Inch End Mill Ultra Precision Extension Holder, Inch Shank

Cuts these materials

AluminumCopper & BrassTitaniumMagnesiumCast IronSteelStainless SteelSuperalloys (Inconel…)PlasticsCompositesHardened 30–40 HRcHardened 41–50 HRcHardened 51–60 HRcWood

See it run

Tolerances

TypeMinMax
Hole Diameter0+0.00015
Overall Length-0.06+0.06
Shank Diameter-0.0001-0.0003
Starting at$464.85

Made & shipped in the USA · lead time confirmed at order. Buy at retail or through your distributor.

Performance guaranteed. Run it against the tool you use today — if it doesn't beat it, we'll make it right.

Adds Uncoated · $464.85 — our pick for your material. Choose another finish below.

Calculate Speeds & FeedsDownload ISO 13399 data (.csv)

Finishes (1)

  • Uncoated

    ACH-M14

    $464.85

    Available to order

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$464.85

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More in the ACH-M series

Same series, different size — what changes from this tool is shown in red.