Installing Cable Rail Tensioners for Wood Posts
Watch this product demonstration of tensioners for wood posts to understand the basic steps of installing Cable Bullet hardware and tensioning cables.
How difficult is this project?
This project is: DIY-friendly
Installing tensioners into existing wood post railing is a straight-forward project. Give yourself extra time when working with hardwood, and around complex stair configurations.
Installing cables in new or existing wood railing is a great way to give any room or deck a modern upgrade and open up the view. Cable Bullet wood post tensioner kits are versatile and will work well in soft and hardwood posts. The coarse thread provides for a solid connection in even soft species, including cedar, redwood and pine, all of which are popular choices for deck builders. If your railing calls for hardwood newels, e.g. oak, maple, or even tropical species like Ipe, simply use the hardwood tap after drilling your pilot holes.
Because Cable Bullet tensioners are machined from type 316 marine grade stainless steel they will look great in any interior setting and resist corrosion in even coastal environments.
Continue reading or download the full installation instructions:
- Drill (1/2” chuck) and drill bits 9/16” & 3/16”
- Tape measure & combination square
- Cable Bullet installation kit (crimper, cable cutters, Bullet driver, 3/32" Allen key & hex power bit)
- Socket screw driver
- Socket wrench with 7/16” head (optional)
- Drill guide (optional)
- Cable Bullet hardwood tap (optional)
- T-10 Star drive (optional)
1.| Project Guidelines
- CABLE TENSIONING POSTS can be spaced up to 20 feet apart. To maintain optimal tension, add tensioners for longer runs.
- ADD CABLE SPACER BARS or cable support posts every 42–48 inches to minimize cable deflection under load.
- SPACE YOUR CABLES every 3 inches apart to allow for some cable deflection while maintaining a 4-inch gap between cable runs.
- SUPPORT YOUR TOP RAIL as needed with structural posts. Consult your builder for post spacing and top rail design on your project.
PLEASE NOTE: All Cable Bullet recommendations and rail components are designed to comply with the International Residential Code (IRC). However, because building codes may vary it is the installer’s responsibility to verify that the installed system complies with all applicable state and local building codes.
For more information on Cable Bullet and building code standards, visit our terms page.
2.| Measuring & Marking Posts
Measure and mark the location for each of your Cable Bullet tensioners.
Do the same for all your intermediate cable pass-through holes.
PRO TIP: Consider your cable placement relative to any stair run to avoid off-set cables.
3.| Drilling & Tapping Holes
4.| Intermediate Posts
PRO TIP: Clamp a piece of wood to the back side of your post to avoid blowout.
5.| Installing Tensioners
Use a drill with a 1/2” chuck and the Bullet driver to screw each Bullet into the posts.
Optional: Use a socket wrench and 7/16” head to align tensioners so the set screw is accessible relative to the angle of the cable.
WARNING: Do not use an impact driver, or you can damage the set screw channel, increasing the likelihood of seizing during installation.
6.| Post Hole Covers (Optional)
Installing Intermediate Post Hardware
Each post-hole cover is secured to the post with one #4-24 x 5/8” stainless steel 6-lobe socket head cap screw using a T-10 x 2” star drive power bit.
For hardwood posts drill a 3/32” pilot hole.
PRO TIP: Use a scrap piece of cable to “hang” your post hole cover in place while fastening it to the post.
7.| Dummy Tensioners (optional)
Drill a 9/16” hole to 1/2” depth, centered on your 3/16” pass-through hole. Use the Bullet driver and a drill or socket wrench to set the dummy tensioner.
PRO TIP: Use dummy tensioners on transitional posts that break a straight run, e.g. at the top of stairs, two-post corners, and 45-degree turns to save on tensioners and protect your post from abrasion and the resulting compression load.
8.| Fixed Spacer Bars (optional)
Spacer Bar Standoff
Spacer bars can be attached to the top rail using a standoff. Drill a 1/8” pilot hole and use a drill to set the standoff, then thread the spacer bar onto the standoff.
PRO TIP: Protect the finish and threads on your standoff during installation with a piece of painter’s tape.
9.| Cutting Rough Cable Lengths
Measure your runs and cut over-sized, rough lengths of cable for each.
NOTE: Be sure to leave an extra few inches so as not to end up short. You will make a finish cut later.
10.| Lubricating Tensioners
Apply a drop of Boeshield T-9 lubricant to the set screw channel of each tensioner to ease installation and reduce the likelihood of seizing, passivate the stainless, and help prevent corrosion.
WARNING: To avoid staining, take special care to avoid spilling T-9 on the surface of your wood surfaces.
11.| Crimping Cable Ends
Fit the first end of your cable with a lobed washer and crimp sleeve. Use the Cable Bullet crimper to firmly set the crimp. This should take 10-12 pumps.
12.| Setting Cable Ends
CAUTION: To minimize the risk of cross-threading or galling, use a manual socket screw driver or Allen key.
13.| Running Cables
With the crimped end locked in place, thread your cable through all intermediate posts and spacer bars (where applicable)
PRO TIP: Tape your floating spacer bars to the closest post until all your cables are set.
14.| Cutting Exact Cable Lengths
Pull the cable hand-tight, measure an inch past the face of the tensioner, and make your finish cut.
Repeat steps 11 and 12 to secure the second end of your cable, then repeat the entire process for each of your remaining cables.
15.| Final Tensioning
Once all your cables are in place, begin tensioning each run from the innermost cable outwards.
How tight is tight enough?
A properly tensioned cable will deflect approximately 1/4” per foot under a 50# load. A properly tensioned wire will feel more like a guitar string, less like piano wire.
16.| Setting Spacer Bars
Position and lock your floating cable spacer bars in place by advancing the set screw top and bottom.