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Technical Information

Direct Bolt Joint*

Direct Bolt Joint*, also known as a 3-Point Registration, is the most robust joint for constructing the frame of your project. This automatically squares your framework when the bolts are fully tightened. (See Law Of Cubing). When bolting 2″ of tube together use a 2-½” bolt, for 3″ of tube use a 3-½” bolt, etc.

*Patented for direct bolt joint

Digital illustration of Flex Craft direct bolt jointing.
Digital illustration of Flex Craft Cubing.

Law Of Cubing

Using Direct Bolt Joints* for the strongest possible construction, use the direct bolt method on as many corners as possible. At a minimum use the direct bolt joint on all outside corners and then fill to fit your needs.

Specifications & Basic Assembly

Our competition can not compete with the versatility of the Patented Flex Craft System. Not only is the Flex Craft Direct Bolt Joint* the strongest on the market, it also aids in the squaring of the project framework every time. This added flexibility allows the end user to make modifications as needed without any special tools or fasteners.

Please note the capacity values listed below and in the PDF are in pounds (lbs.).

Specification diagrams of Flex Craft's 1"x1" and 1"x2" steel tubing.

Evenly Distributed Horizontal Load Rating

Length Between Uprights Steel Aluminum 1″ x 2″ Tall 1″ x 2″ Wide
12″ 970 lbs. 648 lbs. 8,250 lbs. 2,648 lbs.
24″ 480 lbs. 319 lbs. 4,082 lbs. 1,310 lbs.
36″ 304 lbs. 204 lbs. 2,586 lbs. 830 lbs.
48″ 242 lbs. 161 lbs. 2,058 lbs. 661 lbs.
60″ 194 lbs. 130 lbs. 1,650 lbs. 530 lbs.
72″ 148 lbs. 105 lbs. 1,259 lbs. 404 lbs.
84″ 138 lbs. 91 lbs. 1,174 lbs. 377 lbs.
96″ 122 lbs. 81 lbs. 1,038 lbs. 333 lbs.
108″ 104 lbs. 69 lbs. 930 lbs. 295 lbs.
120″ 96 lbs. 50 lbs. 826 lbs. 264 lbs.

The above Load Ratings are based on the Direct Bolt joint, not Bracketed joints.

Calculating Load Capacity Example

  • An evenly distributed load placed on two 36″ steel tubes would start to yield/deflect around 608 lbs. (two tubes x 304 lbs.).
  • Single point load is half the strength of an evenly distributed load.
3D rendering of how to add additional strength to Flex Craft tube structures by adding vertical or horizontal tube supports.

Adding Strength To Structures

Add either (or both) additional vertical or horizontal tube supports for additional strength. Double tubes by bolting two tubes together horizontally or vertically redistributing the load weight from two tubes to four tubes. Another option can include incorporating 1″ x 2″ tubing where extra support is needed.

Technical Specifications

  • Technical specifications are for reference only and are subject to change.
  • Not intended for human support.
  • 1″ x 1″ 16ga mechanical steel tube recommended torque setting of 7.5ft.-lb. and weighs 0.7 lb./ft.
  • 1″ x 1″ 16ga aluminum tube recommended torque setting of 4ft.-lb. and weighs 0.2 lb./ft.
  • 1″ x 2″ 12ga mechanical steel tube recommended torque setting of 12ft.-lb. and weighs 1.81 lb./ft. (Recommended torque settings are to avoid denting the tube.)
  • 1″ x 2″ tube works as a stand-alone framing system and integrates with the 1″ x 1″ system.
  • Bolts used are 5/16-18 UNC.

Casters & Feet

Expandable Casters – Turn the top jam nut snug on the rubber spacer. Place the caster into a tube and twist the large lock ring until the rubber locks in the tube.

Plate Casters – Use 2-3/4″ bolts through two tubes and 1-3/4″ bolts through one tube. Bolt threads must be down, and a nylon lock nut is recommended.

Universal Footers – Attach two brackets on opposing corners of the tube. For a 1″ x 1″ tube use 1-3/4″ bolts in a perpendicular pattern as shown below. For a 1″ x 2″ tube use a 2-3/4″ bolt on top and through both brackets and 1-3/4″ bolts on the bottom. Use Nylock nuts to secure.

Digital illustration of Flex Craft's Casters / Footers.