Welding Table editorial research · September 17, 2026 · Comparison method
Pins, stops and bolts can look similar in a fixture kit, but their jobs differ. A locating element establishes position; a fastener secures components; a stop provides a surface for the workpiece to meet. Some products combine functions, but the name “pin” alone tells you very little.
Before adding a kit to a table, identify what each part does and which dimensions control its fit.
A loose locating pin is not automatically a clamp
A straight pin can provide a reference against which a part is positioned. Unless the product includes a documented locking function, do not assume it retains an attached bracket against upward or side loading.
Similarly, the workpiece resting against a stop still needs the intended holding arrangement. Look at the assembly as a sequence: locate the fixture, secure the fixture, place the workpiece, then restrain the workpiece appropriately.
Stop shape determines the contact you get
A low stop can locate an edge while leaving more of the joint exposed. A taller block or angle may contact an upright face. Adjustable stops provide travel between grid locations, but their adjustment and fastening need to remain accessible after the part is loaded.
Choose a contact face that reaches the intended reference surface. A stop touching a rounded corner or a burr can produce a different position from one contacting the flat wall specified in the drawing.
Grip range is a stack measurement
For a locking fastener, account for all components it must join. A top plate, bracket foot and spacer form a different stack from two fixture plates joined off the table. The correct bore diameter does not select the correct grip length.
Strong Hand offers several 5/8-inch ball lock bolt variants for different arrangements and explicitly excludes T55015 from Alpha 5/8 tabletops. Its locking design engages the underside geometry of the plate. This is a concrete example of why even products within one nominal system need part-level checks.
Check the underside and the release access
A fastener may be operated from above but still require clearance below the plate. Confirm that a rib, shelf or nearby hardware does not obstruct engagement at the selected hole.
Leave room to release the bolt after the job. Flush hardware can help with certain contact surfaces, while a projecting head may be acceptable elsewhere. Choose that feature based on the fixture’s use rather than treating flush and standard versions as interchangeable.
What to keep in a useful fixture inventory
Buy enough locating and fastening elements to complete a known layout, then add the specialized contacts that recurring parts require. Organize them by system and grip range. Two nearly identical bolts with different working lengths should be distinguishable without trying them in a loaded setup.
If a kit description does not identify dimensions or compatible tables, ask for its parts list. Quantity is a poor measure of value when half the pieces do not suit your plate thickness or expected work.
Select pins by their locating role and bolts by the exact components they must secure; keep grip length visible in the purchase decision.
Questions & answers
Can I substitute ordinary bolts for fixture bolts?
Only where the fixture manufacturer permits that fastening arrangement. An ordinary bolt is not automatically a precision locator or a replacement for a specific locking design.
Why does my pin fit but the fixture not lock?
Diameter may be correct while grip range, underside clearance or engagement geometry is wrong. Stop and check the exact table and fastener instructions.