For setting cables in

soft or hardwood posts

Shop >

For fitting cables through

vinyl or composite post sleeves


Tensioners, posts & handrail for

aluminum or steel railing


For anchoring cables to

masonry posts or columns


Guides for installing the Cable Bullet system

View All >

Instructions for treating and preserving your cable railing

Read More >

Metal Post Cable Rail Tensioner: Basic Installation

  • 4 min read

How difficult is this project?

This project is: DIY-friendly

Installing tensioners in Cable Bullet Signature series posts, or custom fabricated metal posts is a simple, straightforward process. The same tensioning hardware can be used on straight, angled, or sloped railing sections.

Whether you are using Cable Bullet Signature series posts or working with a fabricator on a custom solution for your project, nothing says modern elegance quite like aluminum or steel railing. Cable Bullet metal post tensioners feature a finer machine thread ideal for attaching to steel or aluminum post walls.

This guide includes...

  • Signature series full installation video
  • Specifications for custom metal posts
  • How to install metal post tensioners

Continue reading or download the installation instructions:

Signature Series Demo Video

Watch this full installation video on installing Signature Series top mount posts, aluminum handrail, and stainless steel Cable Bullet tensioners.

Installing Signature Series Top Mount Posts and Aluminum Handrail | Cable Bullet Cable Rail System

Working with custom posts?

Cable Bullet tensioners can be used for cable infill with aluminum, steel, or stainless custom metal railing. To make sure your rail design is compatible with Cable Bullet tensioners, follow these specifications.

  • USE 2X2-INCH TUBING (minimum) for strength, and to allow space for two sets of tensioners on opposing or perpendicular sides.
  • STEEL POSTS should have a wall thickness of no less than 3/16”. Drill a 19/37” pilot hole and tap for 5/8-18 threading.
  • ALUMINUM POSTS should have a wall thickness of no less than 1/4”. Drill a 37/64” pilot hole and tap for 5/8-18 threading.




  • Cable Bullet installation kit (crimper, cable cutters, Bullet driver, 3/32" Allen key & hex power bit)
  • Socket wrench with 7/16” head (optional)
  • Hex socket power bit (optional)


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.

1.| set tensioners

Thread tensioners into metal post.

Thread the tensioners into the post and use the Bullet driver A and a socket wrench with a 7/16” socket to align the tensioners so the set screw is accessible relative to the angle of the cable.

2.| Lubricate Tensioners

Lubricate tensioners with a drop of Boeshield T9

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.

3.| fixed spacer bars (optional)

Attach fixed spacer bars to top rail.

Spacer Bar Standoff
Fixed spacer bars attach to the top rail using a standoff. Use a #25 drill bit for the pilot hole, and tap for 10-24 NC. 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.

4.| cut rough cable lengths

Cut rough cable lengths

Measure your runs and cut oversized, rough lengths of cable for each. Leave an extra few inches so as not to end up short. You will make a finish cut later.

5.| crimp cable ends

Properly crimp 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. A properly crimped cable end will show a distinct hexagonal imprint pattern.

CAUTION: A properly crimped cable end is essential to maintaining the integrity and safety of your cable. A weak connection will slip over time or fail against an impact load!

6.| set cable ends

Set crimped cable end in tensioner

Insert the crimped cable and lobed washer into the tensioner and use a 3/32” Allen key or hex socket power bit to advance the set screw until it is flush with the face of the Bullet.

CAUTION: To minimize the risk of cross-threading or galling, use a manual socket screw driver or Allen wrench.

7.| run cables

Run cable through any intermediate posts and spacer bars

With the crimped end locked in place, thread your cable through all the intermediate posts and spacer bars.

PRO TIP: Tape your floating spacer bars to the closest post until all your cables are set.

8.| cut exact cable lengths

Measure and cut exact cable lengths

Pull the cable hand-tight, measure an inch past the face of the tensioner, and make your finish cut.

Repeat steps #5 and #6 to secure the second end of your cable, then repeat the entire process for each of your cables.

9.| final tensioning

Tension each cable length to proper tightness

Once all your cables are in place, begin tensioning each run from the innermost cable outwards.

How tight is tight enough?
Take care not to over-tighten the cables. A properly tensioned cable will deflect approximately 1/4” per foot under a 50# load.

10.| set spacer bars

Set spacer bars in place using Allen key. Ensure cables are level.

Position and lock your floating cable spacer bars in place by advancing the set screw top and bottom.

Care & Maintenance

After you’ve finished the installation process, follow the Cable Bullet Care & Maintenance Instructions to make sure your cable railing looks great for years to come!

Site Search