Welding Table editorial research · September 17, 2026 · Comparison method
A welding table hole has two separate jobs: it receives a fixture and establishes a location. Bore diameter controls the first; the spacing between hole centers controls the second. A listing that gives only “16 mm holes” leaves half the buying question unanswered.
Record the table’s actual system name as well as its dimensions. Rounding an imperial specification into millimeters can make two incompatible systems look identical in a comparison table.
Diameter is measured across; pitch is measured between centers
Hole diameter describes the opening. Grid pitch describes the center-to-center distance between neighboring holes, often in both directions. Neither number tells you how thick the top is or how much room a locking mechanism has beneath it.
For example, Strong Hand documents a 5/8-inch system on a 2-inch grid. Its published diameter and pitch tolerances are separate specifications. A nominal size identifies the family; the tolerance defines the allowed dimensional range for that particular product.
Keep these labels separate
These are system examples, not a universal standard for every table sold under the same nominal diameter. Look for a dimensioned drawing when the listing is abbreviated.
| Label | What it means | What it does not prove |
|---|---|---|
| 5/8 inch | 15.875 mm nominal diameter | Compatibility with a 16 mm clamp |
| 16 mm | A metric nominal diameter | A particular grid pitch or top thickness |
| 2-inch grid | 50.8 mm center-to-center spacing | A 50 mm multi-pin fixture will align |
| 28 mm | A larger nominal bore | That all 28 mm locking bolts share a grip range |
Why one clamp may fit when a bracket does not
A single-post clamp uses one hole. A bracket secured by two fixed pins has to match two holes simultaneously. Even if both pins individually enter a bore, the bracket may fail to seat because the distance between them is wrong.
A slotted attachment may accommodate adjustment, but that is a feature to verify in its drawing. It is not evidence that all accessories in the same brand range will fit. Do not hammer a pin into place or enlarge a table hole to rescue an unverified purchase.
The dimension hidden under the top
Top thickness matters wherever a bolt clamps a stack of parts together. A fastener designed for one plate and one bracket may not lock through a thicker top, an added spacer and a riser. Underside ribs can also obstruct the intended position.
Ask for the fastener’s supported grip range and the exact installation diagram. “Fits 5/8-inch holes” identifies the opening, not every possible stack of components above and below it.
Measure for identification, then confirm the part
On a used table, remove loose debris before measuring and compare several clean holes. Measure center spacing over multiple intervals if possible, dividing by the number of intervals rather than the number of holes. This can help distinguish a rounded listing from an actual different grid.
Workshop measurements help identify a candidate system; they do not certify its tolerance, condition or load rating. Before ordering a fixture set, send the supplier the table make, exact model, bore specification, pitch, top thickness and intended accessory number.
Write down diameter, pitch, plate thickness and accessory identity before treating a hole pattern as compatible.
Questions & answers
Why do welding tables have holes?
They provide attachment and positioning points for compatible clamps, stops and fixtures. The hole pattern does not by itself certify flatness or fume extraction.
Is every welding table on a 2-inch grid?
No. Metric systems and proprietary patterns exist. Check the drawing for the exact table instead of inferring spacing from its hole diameter.