Precision you can
read, not just
take our word for.

HSK tool holders for CNC machining centers and routers, $120–$300. Each holder ships with its own measured runout, balance grade, and taper/face contact verification — signed, dated, and tied to the serial number on the flange.

Shop holders by HSK size


See a sample inspection record

Runout guaranteed ≤ 0.003 mm at 3×D
G2.5 @ 25,000 RPM balance
30-day returns, no restocking fee
INSPECTION RECORD
SN 63A-32-0’4471
RADIAL RUNOUT @ 3×D
0.0021 mm
Spec ≤ 0.003 mm
BALANCE GRADE
G2.5
@ 25,000 RPM
TAPER CONTACT
94.2 %
Spec ≥ 90 %
FACE CONTACT
0.002 mm
Simultaneous fit
Measured on a Zeiss CMM
Inspector: J. Ruiz · 2026-08-14
PASS

Start where your machine is

Two different jobs, two different paths. Pick yours and we’ll only show holders that fit.

Path 01 — Machining centers

I know my spec and need spares

Search by exact designation — HSK63A, HSK100A, form A or F — and check real-time stock. Every holder page shows its inspection record, tightening torque, and gauge line dimensions.

HSK50A / 63A / 63F / 80A / 100A in stock
ER collet chucks, shell mill, shrink-fit, side lock
Volume pricing at 5+ units, net-30 for shops
Browse the parts catalog
Path 02 — CNC routers

I’m new to HSK and need the right size

Most router spindles take HSK63F. Answer three questions about your spindle and we’ll return the exact holder, collet range, and wrench — or start from a kit that has all three.

Spindle sizing tool — 3 questions, no account
Starter kits: holder + collet set + wrench
Plain-language guides on taper, balance, torque
Find my size
Shop starter kits

Shop by HSK size

All 412 holders →
HSK50
Compact machining centers

Form A and E. Common on small verticals and 5-axis trunnion machines.

48 holders
HSK63
The shop workhorse

Form A for machining centers, form F for router spindles.

137 holders
HSK80
Heavy roughing

Higher torque transmission for larger face mills and shell arbors.

61 holders
HSK100
Large-envelope work

Form A for big verticals, horizontals, and boring mills.

84 holders

What’s in the record

Three measurements, taken on the holder you receive. Unbranded imports skip all three; the premium brands charge $250–$1,000 for them.

01
Measured runout

Radial runout read at three diameters out from the gauge line on a CMM, not a bench indicator. The number you get is the number on the paper.

≤ 0.003 mm at 3×D
02
Verified balance grade

Balanced and then re-measured at operating speed. We publish the grade and the RPM it was measured at, because one without the other means nothing.

G2.5 @ 25,000 RPM
03
Taper & face contact

Contact area checked with marking compound and a face-fit gauge to confirm the holder seats on both the taper and the flange face.

≥ 90 % taper contact

Not sure which taper you have?

Sizing, conversion, and balance-grade guides written by machinists — no sign-up, no gated PDFs.

Open the resources hub

HSK sizing guide — find your spindle
→


CAT / BT to HSK conversion chart
→


Balance grades: G2.5 vs G6.3
→