Buying task · Clamps, T-track and inserts
CNC workholding: clamps, T-track and threaded inserts by thread
Match CNC hold-down clamps, T-track and inserts to your table's thread (M6, 1/4-20 or M8) or track, pick the clamp type for the job and the bolt length that fits.
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Picks that fit
- Genmitsu Upgrade CNC Router Vise Clamp, low-profile aluminum toe clamp (101‑63‑VC), 2 or 4 piecesCheck price on Amazon
- E-Z LOK E-Z Hex threaded insert for soft wood, flanged, M6‑1.0 x 13 mm (900610‑13), 50 packCheck price on Amazon
- E-Z LOK E-Z Hex 1/4‑20 x 10 mm flanged insert installation kit for soft wood (EZ‑901420‑10)Check price on Amazon
Short answer
Start from your table: buy clamps, bolts and inserts in the thread it already uses (M6, 1/4-20 or M8) or the track profile it has, because those threads do not interchange. Then pick the clamp type for the job, size the bolts to the clamp and stock, and set every toolpath so the bit stays clear of the clamps.
Picks that fitAll picks and how to choose
- Genmitsu Upgrade CNC Router Vise Clamp, low-profile aluminum toe clamp (101‑63‑VC), 2 or 4 piecesCheck price on Amazon
- E-Z LOK E-Z Hex threaded insert for soft wood, flanged, M6‑1.0 x 13 mm (900610‑13), 50 packCheck price on Amazon
- E-Z LOK E-Z Hex 1/4‑20 x 10 mm flanged insert installation kit for soft wood (EZ‑901420‑10)Check price on Amazon
What workholding has to do
A CNC cuts with the stock fixed to the spoilboard or table. Hold-down clamps press on the top or the edge of the stock, and bolt into a threaded insert, a T-track or a hybrid table. OSHA's router guidance lists poorly fixed stock among the causes of kickback and advises securing it.[1] Tapes and adhesives are out of scope here.
The decisions, in order
1. Your table's thread or track. M6 and 1/4-20 are different threads. Carbide 3D says the M6 hardware with its Essential Clamps is for its Hybrid Table and Teez-Nutz, and that the clamps can be used with 1/4-inch hardware on your own T-track or threaded inserts.[3] That is a choice of hardware, not a sign the threads interchange. Onefinity said in an official post that its QCW uses a 1/4-20 track.[4] Rockler's Universal T-Track is 3/4 in wide by 3/8 in deep[5] and accepts 5/16 in T-bolts, 1/4 in T-bolts and 1/4 in hex bolts.[5] If you are adding inserts to an MDF board, Carbide 3D sells M6 x 1 and 1/4-20 inserts, 13 mm long, and recommends a 9 mm pilot hole;[6] E-Z LOK gives a different drill for each M6 insert type.[7] See M6 vs 1/4-20 spoilboard threads.
2. Clamp type for the job. Carbide 3D's Shapeoko Essential Clamps package lists 4 clamps with 4 M6 x 20 and 4 M6 x 30 socket head screws.[3] Its Crush-It clamps are not intended for the Shapeoko 3, which has no Hybrid Table, but can be used on a fixture plate with M6 holes.[8] Genmitsu's low-profile toe clamp uses M6 screws and nuts and measures 106 x 22 x 15 mm,[9] listed for T-track tables, hybrid tables and MDF or aluminum spoilboards with M6 holes on Genmitsu 4030 and larger machines.[9] The clamp types guide compares top, toe and low-profile clamps.
3. Bolt length. Carbide 3D's Crush-It Nutz 'n Bolts kit holds M6 x 1.0 bolts, six each in 16, 20, 25, 30, 35 and 40 mm, plus 12 Teez Nutz, for its Hybrid Table machines.[10] Insert length matters too: Carbide 3D staff said 10 mm M6 inserts can replace 13 mm ones if every bolt is 3 mm longer.[11]
4. Keep clamps out of the toolpath. No clamp maker we read publishes a clearance figure, so check the toolpath preview against where each clamp sits before every job.
How to choose
Pick the thread first, then the hardware. These approved parts state theirs.
Picks that fit5 products
M6 tables: Genmitsu low-profile toe clamp (choose the 4-clamp 101-63-VC-4P or the 2-clamp -2P) and E-Z LOK 900610-13 M6 inserts for MDF or other soft wood. 1/4-20 tables: E-Z LOK EZ-901420-10, ten 1/4-20 x 10 mm inserts with drill and drive tool, for soft wood.
More on choosing
Track: POWERTEC 71373, four 48 in universal tracks, and POWERTEC QTB1006 1/4-20 T-bolts, 3-1/2 in long, which POWERTEC says fit universal track, not 1/4 in or mini track. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or the brand.
M6 inserts for an MDF spoilboard
E-Z LOK E-Z Hex threaded insert for soft wood, flanged, M6‑1.0 x 13 mm (900610‑13), 50 pack
1/4-20 insert kit for soft wood
E-Z LOK E-Z Hex 1/4‑20 x 10 mm flanged insert installation kit for soft wood (EZ‑901420‑10)
Universal T-track for 1/4-20 and 5/16-18 hardware
POWERTEC 71373 48 in double-cut profile universal T-track, 4 pack
1/4-20 T-bolts for universal track
POWERTEC 1/4‑20 T-track bolts, 3‑1/2 in long, 20 pack (QTB1006)
Every page on workholding
Guides
- M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fits
- Threaded inserts for a CNC spoilboard: thread, wood and drill size
- T-track for CNC hold-downs: profile, bolts and miter track
- CNC hold-down clamps: top, toe, low-profile and stops
Your machine's table
- CNC part finder by machine and Z axis: each machine page lists its table and workholding thread where the maker states it.
Key terms
M8 thread, pilot hole, T-slot profile, T-bolt, miter track, toe clamp, clamp step and dovetail track.
Everything in this topic
Guides
- CNC hold-down clamps: top, toe, low-profile and stopsHelps you choose a clamp type that fits your table's thread and leaves the toolpath clear.
- M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fitsHelps you buy clamps, bolts and inserts in the thread your table already uses.
- T-track for CNC hold-downs: profile, bolts and miter trackHelps you pick T-track and bolts that fit each other and your clamps.
- Threaded inserts for a CNC spoilboard: thread, wood and drill sizeHelps you choose a threaded insert and the drill its maker specifies for your spoilboard material.
Shortlists
- CNC clamps, T-track and inserts with the thread statedHelps you buy workholding in the thread or track your spoilboard already uses.
Common questions
Which clamps keep the bit away from the clamp?
None guarantees it. Low-profile and edge clamps sit lower or off the top face, but you still have to plan toolpaths around every clamp and check the clearance before you run the job. More in CNC hold-down clamps: top, toe, low-profile and stops
Top clamp or edge clamp for sign work?
If you are carving the whole top face, a top clamp sits in the way, so edge or low-profile clamps make sense; Carbide 3D announced its Tiger Claw for setups where clamping the top face is not an option. For through-cuts and parts with spare margin, top clamps outside the cut area work. More in CNC hold-down clamps: top, toe, low-profile and stops
Are nylon clamps safe to hit with a bit?
No maker claim we found says so, and you should not rely on it. Plan toolpaths so the bit never reaches any clamp. More in CNC hold-down clamps: top, toe, low-profile and stops
Can a person hold the work instead of a clamp?
No. CCOHS advises never relying on yourself or a second person to hold the material being routed, and OSHA lists poorly fixed stock among causes of kickback. More in CNC hold-down clamps: top, toe, low-profile and stops
Can I buy extra Crush-It jaws?
Carbide 3D says extra jaws come with the Crush-It Essential set but are not sold separately. More in CNC hold-down clamps: top, toe, low-profile and stops
Is my spoilboard M6 or 1/4-20?
Check the machine or table maker's documentation, or the hardware that came with it. Carbide 3D's Hybrid Table hardware is M6, and Onefinity said in 2021 that its QCW uses a 1/4-20 track. More in M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fits
Can I mix M6 and 1/4-20 clamps?
Only if each clamp gets bolts in the thread of the hole or track it goes into. A clamp body may accept either bolt (Carbide 3D says its Essential Clamps can be used with 1/4 inch hardware on your own track or inserts), but an M6 bolt and a 1/4-20 bolt are not interchangeable. More in M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fits
What thread does a Onefinity QCW use?
Onefinity stated in an official October 2021 forum post that the QCW uses a 1/4-20 track and that a standard 1/4-20 bolt head fits. More in M6 vs 1/4-20 (and M8) spoilboard threads: which hardware fits
Questions
What clamps fit an M6 table?
Clamps whose maker lists M6 hardware. Genmitsu's low-profile toe clamp uses M6 screws and nuts and is listed for M6 spoilboards, hybrid tables and T-track, and Carbide 3D's Essential Clamps ship with M6 screws for its Hybrid Table.[9][3]
Do I need T-track or threaded inserts?
Either works if the clamp hardware matches. Carbide 3D says its Essential Clamps can be used with 1/4-inch hardware on your own T-track or threaded inserts. Inserts give fixed points in an MDF board; track lets a bolt slide along a line.[3]
Which clamps suit edge or sign work?
Low-profile toe or side clamps that grip the edge leave the top face clear for the toolpath. Genmitsu's toe clamp is 15 mm tall; whatever you use, set the toolpath so the bit never reaches the clamp.[9]