How to Install a Stainless Steel Top Rail with Self-Tapping Screws
Use this method to fasten an Inline Design stainless-steel top rail to the post saddles with #10 × 3/4 in. Phillips truss-head screws. Spot-drilling a 11/64 in. hole makes installation into stainless-steel tubing easier and reduces the risk of damaging the screw.
Application: Stainless-steel top rail to post saddle only. These screws are not intended for anchoring railing posts to a deck, concrete, framing, or another supporting structure.
Stainless steel only: These instructions and the 11/64 in. spot-drill size apply to Inline Design stainless-steel tubing. For black matte aluminum tubing, use the aluminum top-rail instructions; the aluminum method does not use a pilot hole with the recommended self-drilling screw.
Select the Correct Stainless-Steel Finish
Satin Stainless Steel
#10 × 3/4 in. natural-finish Phillips truss-head screw
View recommended satin screwBlack Stainless Steel
#10 × 3/4 in. black-finish Phillips truss-head screw
View recommended black screwAn equivalent screw may be used only when it has the same #10 diameter, 3/4 in. length, Phillips drive, truss head, and a thread or drilling point suitable for stainless steel. Do not use flat-head, countersunk, drywall, or wood screws.
Tools and Materials
Installation Procedure
Dry-Fit the Top Rail
Place the stainless-steel top rail on the post saddles. Confirm that the posts are plumb and aligned and that the rail is fully seated on every saddle.
Verify the Complete Run
Check all corners, joints, transitions, and end overhangs. Hold the top rail securely in its final position before drilling.
Spot-Drill the Rail
Use the existing hole in each saddle as the drill guide. With an 11/64 in. cobalt bit, drill through the lower wall of the top rail only. Use slow speed, steady pressure, and a small amount of cutting fluid.
Remove Metal Shavings
Remove all drilling chips from the saddle, top rail, and nearby finished surfaces. For black stainless-steel railing, touch up any coating damaged during drilling before final assembly.
Install the Screw
Insert the screw through the saddle and into the prepared hole. Keep the screw perpendicular to the tubing and drive it slowly using a #2 Phillips bit.
Seat and Inspect
Stop when the screw head is firmly seated against the saddle. Confirm that the rail is tight, the saddle is not distorted, and the screw does not spin freely.
Critical Installation Requirements
- Do not drill through the upper wall of the top rail.
- Do not use an impact driver.
- Do not overtighten the screw.
- Keep the drill chuck away from the finished rail surface.
- Remove all metal shavings immediately after drilling.
Alternative Drill-and-Tap Method
The top rail may instead be installed with M5 × 0.8 machine screws by drilling and tapping threaded holes in the tubing.
View the M5 drill-and-tap instructionsInstalling an Aluminum Top Rail?
Black matte aluminum tubing uses a different procedure. With the recommended self-drilling screw, do not use the 11/64 in. stainless-steel spot-drill specification and do not pre-drill the aluminum.
View the aluminum top-rail instructionsWear appropriate eye and hand protection when drilling or installing metal components. The installer is responsible for confirming that the railing, post anchorage, supporting construction, and completed installation comply with the applicable project requirements and building codes.