Guide · Clamps, T-track and inserts
T-track for CNC hold-downs: profile, bolts and miter track
The track's slot profile decides which bolt heads slide in. What Rockler, POWERTEC and Onefinity state about T-track, T-bolts and miter track.
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Short answer
With T-track, the slot profile decides which bolt heads slide in, and the bolt's thread decides which clamps it takes. Buy track and bolts the track maker lists together: Rockler, for example, says its Universal T-Track accepts 5/16 inch and 1/4 inch T-bolts and 1/4 inch hex bolts.[1] A miter track is a different profile.
Two checks: profile and thread
A T-bolt has to pass two tests. Its head has to fit the slot, and its thread has to fit your clamp or knob. A thread match alone does not prove a bolt fits another maker's track.
Track makers do not always publish the slot shape. Rockler publishes Universal T-Track's outside size and the bolts it accepts, but not the slot opening or internal cavity dimensions.[1] So stay with the bolts each maker names.
Rockler Universal T-Track
- Extruded aluminum, 3/4 inch wide x 3/8 inch deep, in 2, 3 and 4 ft lengths.[1]
- A "stacked" slot that accepts 5/16-18 and 1/4-20 T-bolts and 1/4-20 hex bolts.[2]
- Pre-drilled base holes 4 inches on center, 2 inches from each end. Mounting screws are not included; Rockler recommends #6 flat head screws.[1]
Rockler's 5/16-18 T-bolts have bottom plates 9/16 inch wide x 7/8 inch long x 7/64 inch high, in zinc-plated steel.[3] Its T-Track Drop-Ins fit 3/4 inch wide, 3/8 inch deep grooves, work with the same three bolt types, and form intersections, ends or a drop-in entry point for bolts.[2]
POWERTEC track
POWERTEC sells several profiles. Its Standard Miter T-Track is anodized aluminum in 32 and 48 inch lengths, designed for 3/4 x 3/8 inch T-bars.[4] That page lists no bolt slot, so treat it as a miter-bar track, not a hold-down track.
POWERTEC says its catalog products are sold only on its own site, Amazon, eBay, Home Depot and Walmart.[5]
Picks that fit2 products
For hold-downs, choose the 71373 universal T-track (four 48 in tracks; POWERTEC lists it for 1/4 in hex bolts and 1/4 in and 5/16 in T-bolts, screws not included) and the QTB1006 1/4-20 T-bolts, 3-1/2 in long, 20-pack.
More on choosing
Not the miter-only track. If buying on Amazon, check that Ships from / Sold by is Amazon.com or POWERTEC.
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)
Miter track vs hold-down track
A miter track is shaped for a flat miter bar that slides along it. A hold-down track has an undercut slot that traps a bolt head so you can pull a clamp down. A track sold only for miter bars gives no proof that clamp bolts will fit. For hold-downs, buy a track whose maker lists the bolts it accepts.
Onefinity QCW
Onefinity stated in an official October 2021 forum post that its QCW uses a 1/4-20 track and that a standard 1/4-20 bolt head fits.[6] The post gives no head dimensions, so check a bolt in the slot before buying a large pack.
| Track | Profile stated | Bolts stated |
|---|---|---|
| Rockler Universal T-Track | 3/4 x 3/8 in outside; slot not published | 5/16-18 and 1/4-20 T-bolts, 1/4-20 hex bolts |
| POWERTEC Standard Miter T-Track | For 3/4 x 3/8 in T-bars | None listed |
| Onefinity QCW | 1/4-20 track | Standard 1/4-20 bolt head |
Spacing
We found no track maker that gives a spacing for CNC tables. Follow your machine or table maker's layout, keep tracks clear of the bit's path, and plan them around the clamps and stock sizes you use.
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Questions
Will 1/4-20 hex bolts fit T-track?
In some tracks. Rockler says its Universal T-Track's stacked slot accepts 1/4 inch hex bolts as well as 1/4 and 5/16 inch T-bolts. Other tracks need the bolt their maker names.[1]
Is miter track the same as T-track?
No. POWERTEC's Standard Miter T-Track is designed for 3/4 x 3/8 inch T-bars, and its page lists no bolt slot, so treat it as a miter-bar track, not proof that clamp bolts fit.[4]
How far apart should T-tracks be on a CNC?
No track maker we found gives a spacing for CNC tables. Follow your machine or table maker's layout and plan it around the clamps and stock sizes you use.