What are the benefits to using a Modular Fixture Plate on a CNC machine?

Modular fixture plate benefits include:

  1. Increasing the workholding, clamping and setup area
  2. Convenience of having hundreds of bored and tapped holes versus a few t-slots
  3. Indexing, shifting, locating and holding large parts
  4. Clamping large parts outside of the machining envelope
  5. Using the SMW Mod Vise low profile, modular work holding system!
  6. Protecting the CNC machine table (often made from soft cast iron)
  7. Quickly aligning, tramming, and clamping vises and other workholding
  8. Using custom, hot-swappable fixture plates tops

Should I buy an aluminum or steel Fixture Plate?

Steel Benefits: Machined from 4140 alloy steel at 30 HRC, these are our premier line of fixture plates. The high quality, surface ground, hardened alloy steel means these fixture plates are the strongest and toughest, well suited for daily use.

Aluminum Benefits: lower price and lighter weight means reduced shipping cost and easier installation. 
7075 Anodized Aluminum fixture plates are an excellent mix of value, weight, and strength. 7075 aluminum has nearly twice the tensile strength as 6061. The anodized surface increases wear resistance, helps reduce scratches, and offers galvanic corrosion resistance. Threaded holes are form tapped for maximum strength.

6061 Aluminum fixture plates are our value line offering. We take pride in the manufacturing process and tolerances of these plates and they are a great way to increase the workholding envelope, implement the SMW mod vise system, and minimize setup time on your CNC machine! Threaded holes are form tapped for maximum strength. NOTE: these plates must be used with a galvanic corrosion inhibitor (e.g. dielectric spark plug grease) and be removed frequently to inspect for condition and/or re-apply the corrosion inhibitor.

What is the Fixture Plate hole spacing?

Standard 1/2" SMW fixture plate holes are spaced 1.25" on center.

1/4" "hobby" plates are spaced 0.75" on center.

Is each hole bored and threaded?

Yes, each hole is precision bored 0.25" deep for use with a 1/2" dowel pin, the SMW Mod Vise or other 1/2" accessories.   Below the precision 1/2" bore, each hole is tapped 1/2"-13 UNC.

Each hole in our 1/4" hobby line is threaded 1/4"-20 UNC, however in most cases holes are not bored. Please see the product page/drawing for specific information.

What Torque Specs should I use on the Fixture Plate?

We recommend 60 ft-lb (81 N-m) for the low-profile SHCS that secure the fixture plate to the T-Nuts. NOTE: This value is only for our standard 1/2-13UNC low-profile SHCS which are common on most Tormach and Haas fixture plates. Please verify the maximum acceptable torque for bolts and mounting hardware of other sizes.

The appropriate torque when using the fixture plate for workholding depends on a variety of factors, including the thread engagement of the stud or screw into the fixture plate. 

For the 1/2x13 holes in aluminum plates, we recommend up to 45 ft-lb or 61 N-m.  DO NOT exceed 50 ft-lb or 68 N-m.    

For the 1/2x13 holes in steel plates, we recommend up to 50 ft-lb or 68 N-m. Do not exceed 70 ft-lb (94 N-m). 

What is the greasy, sticky stuff on my fixture plate?

We apply a light coat of LPS3 to steel fixture plates and other products prior to packaging and shipping.  This can be easily removed with traditional solvents or cleaners such as WD-40 or acetone.  We recommend leaving steel products lightly coated with a rust inhibitor, particularly for shops located in environments prone to rust (e.g. high humidity, near saltwater, etc). Refer to article on for tips on avoiding rust in the machine shop.

Why does my aluminum plate have four set screw in the back?

These are used for fixturing during the anodizing process

Do you provide Solid Models?

Yes, click here

Note: Solid models and drawings are being added directly to product pages where applicable. The above page will no longer be updated but will remain accessible.

Will you create a custom plate for my machine?

Please contact us via this form.

How do I setup and install my SMW Fixture Plate?

Click here to watch our instructional video

How do I prevent rust on my fixture plate?

Click here to read our article on machine shop rust prevention

What maintenance do I need to do on my Fixture Plate?

We recommend any workholding device (fixture plate, vice, 4th axis, etc) be periodically removed and cleaned.  This interval depends on personal preference, frequency of use, types of material being cut, coolant and more but generally should be inspected every 3-12 months.  See FAQ item above for tips on preventing rust.

What is the leadtime on Fixture Plates? Do you keep them in stock?

Many products are kept in stock and thus ship within one day of order.  However, please contact us to confirm inventory and leadtime for urgent orders

Used Fixture Plates

Occasionally (albeit infrequently) "used" plates will be added to the store at a slight discount. These plates are still functional but have been previously installed (typically used in the SMW shop) and may have slight cosmetic defects.

Mod Vise

How do I use my SMW Modular Vise System?

Click here for our instructional video on how to use your Mod Vise

What is the difference between the Pitbull and Tiny Vise version?

Tiny Vise: each Tiny Vise clamp offers two clamping edges:  one serrated edge for better gripping and one smooth edge for lighter, but non-marring clamping.  
Pitbull:  The Pitbull clamps use the Mitee-Bite Pitbull clamp which offers higher clamping forces than the Tiny Vise.  We generally prefer using the Pitbull for this reason.

Will Mod Vises work with non-SMW fixture plates?

Mod Vises require the unique combination of having each fixture plate hole both bored for 1/2" precision pins and tapped 1/2x13".   Generally speaking, the Mod Vise will not work on other brands of fixture plates.



What is the parallelism tolerance of an SMW Fixture Plate?

SMW Fixture Plates are held to parallelism of +/- 0.0005" per 18" .

What tolerance is the flatness of a SMW Fixture Plate held to?

We do not qualify plates in an unconstrained state.  However, we do evaluate and process the raw material in a specific way so that when the fixture plate is secured to the machine table, it's "flatness" will be the result of the parallelism tolerance plus any deviation, level, or tram error in the machine table.

How precise is the bored hole diameter on a SMW Fixture Plate?

The 1/2" precision bores on the SMW Steel Fixture plates are machined to 0.5005" +/- 0.0002".  We have found this to be the ideal tolerance when using a mix of dowel pins, gauge pins and accessories like the SMW Mod Vise.  Keep in mind, for a dowel pin to have a "slip" fit (e.g. not require hand tools, vice grips, etc to remove), there must be some gap or "slop" in the fit between the pin and the hole.  
The 1/2" precision bores on the SMW aluminum fixture plates are held to approximately 0.5005" +/-0.0004".  The additional tolerance range is due to the variability of the anodizing process.

What if a dowel pin has a loose fit?

Dowel pins can be purchased with varying degrees of tolerance and fit, but traditional "off the shelf" dowel pins (e.g. this 1/2" dowel pin from McMaster Carr) have dimensional tolerance of 1/2" +0.0001 to +0.0003.  A pin cannot fit in a hole of the same size; the hole must be larger.  Our hole tolerance, as described above, allows for this fit.   However, adding a relatively small amount to a bore diameter - even 0.0001" results in a notable difference in the feel and fit of how a pin fits into a hole.  We use a combination of metrology tools, including bore gages and deltronics gage pins, to ensure bores meet our tolerances.