Double connection guidelines

A clipped end connection is a structural connection where the end of an incoming member is notched so the notch fits around the nut or bolt head of the first member, allowing the second member to be bolted up without removing the bolt holding the first member. See the non-mandatory illustration in Appendix H to Subpart R which explains clipped end connections as a way to comply with 1926.756(c)(1).

• Purpose: lets the erector keep at least one bolt in place while attaching the second member so the common member remains secured.
• When to use: useful when geometry allows cutting a notch without weakening the member or interfering with design tolerances.

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)

A staggered connection uses offset or extra bolt holes in the common member so that the two incoming members do not share the same bolt holes, allowing the erector to maintain at least one bolt connection at all times while making the double connection. Appendix H shows a staggered connection as a non-mandatory guideline for complying with 1926.756(c)(1).

• How it works: one incoming member is bolted using one set of holes while the second member is prepared using a different, adjacent hole; this prevents removal of the only bolt holding the common member.
• Advantage: avoids cutting or notching material when member geometry or strength considerations make clipped ends impractical.

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)

No. Appendix H provides non-mandatory guidelines and illustrations; it does not create mandatory requirements. Employers must, however, meet the substance of 1926.756(c)(1), and Appendix H illustrates two practical ways (clipped end and staggered connections) to comply. See the Appendix title: "Non-Mandatory Guidelines for Complying With 1926.756(c)(1)" in Appendix H to Subpart R.

• In short: you are not required to use the exact details in Appendix H, but you must achieve the safety objective of 1926.756(c)(1).

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)

Maintaining at least one bolt connection prevents the incoming common member from being completely unsecured while the erector installs the remaining bolts, reducing the risk of displacement or collapse. This safety objective is what 1926.756(c)(1) addresses; Appendix H illustrates clipped end and staggered connections as practical ways to meet that objective in Appendix H to Subpart R.

• Safety effect: ensures temporary stability, reduces need for makeshift supports, and helps protect erectors from sudden member movement.

(Reference: 1926.756(c)(1) and Appendix H to Subpart R.)

No—erectors must not remove the only bolt securing the common member before the second incoming member is secured; they must ensure the common member remains attached by at least one bolt while completing the double connection. Appendix H illustrates clipped end and staggered methods that allow bolting the second member without removing the first bolt in order to meet 1926.756(c)(1).

• Practical point: if your connection method requires temporarily removing a bolt that leaves the common member unsecured, choose an alternate method (clipped end, staggered hole, or other compliant technique).

(Reference: 1926.756(c)(1) and Appendix H.)

Choose the method that maintains at least one bolt connection and suits the member geometry, strength, and fabrication constraints—use a clipped end when notching the member is feasible without compromising strength, and use a staggered connection when adding or using offset bolt holes is preferable. Appendix H describes both options as non-mandatory ways to comply with 1926.756(c)(1) in Appendix H to Subpart R.

• Considerations:
  • Structural design and engineer approval for any notch or hole location
  • Fabrication practicality and field tolerances
  • The need to avoid weakening members or creating stress concentrations

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)

Yes—while Appendix H is non-mandatory, practical steps include ensuring the notch fits cleanly around the opposing bolt head or nut, verifying the notch does not reduce required member strength, and visually inspecting bolt engagement and bolt torque after assembly to confirm the common member remained secured throughout. These are consistent with the compliance objective in 1926.756(c)(1) and the guidance in Appendix H.

• Recommended checks:
  • Confirm notch dimensions and location against fabrication drawings or engineer approval
  • Inspect that the retained bolt is fully engaged and not carrying unintended shear beyond design
  • After completion, confirm all bolts are installed and tightened per specifications

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)

Plan staggered connections by providing an extra or offset bolt hole in the common member web so that one incoming member can be bolted while at least one bolt connection to the other member remains in place; document the hole pattern on shop drawings or field erection plans to ensure installers can maintain a one-bolt connection during assembly, consistent with 1926.756(c)(1) and the illustration in Appendix H.

• Shop planning tips:
  • Show staggered hole locations and tolerances on fabrication drawings
  • Coordinate with the project engineer if additional holes affect strength
  • Communicate the assembly sequence to field erectors so they maintain at least one bolt in place

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)

No—the illustrations in Appendix H to Subpart R are non-mandatory examples showing clipped end and staggered connections; employers are not required to follow them word-for-word so long as their chosen method achieves the safety requirement of 1926.756(c)(1) (maintaining at least one bolt connection while making a double connection).

• Practical implication: alternative methods that provide equivalent or better safety are acceptable if they meet the standard’s objective.

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)

If clipped end or staggered holes are infeasible, the erector must use another method that keeps the common member secured by at least one connection while installing the second incoming member so as to comply with 1926.756(c)(1); Appendix H provides examples but does not limit acceptable alternatives in Appendix H to Subpart R.

• Recommended actions:
  • Consult the project engineer for an approved temporary retention method (shims, clamps, or approved temporary brackets) that maintain at least one secure connection
  • Document the alternate method and ensure it does not compromise structural integrity

(Reference: 1926.756(c)(1) and Appendix H to Subpart R.)

Yes—while Appendix H shows typical methods, any notch or extra hole that could affect member strength should be reviewed and approved by the project's engineer of record to ensure structural integrity and compliance with 1926.756(c)(1). Appendix H is non-mandatory guidance in Appendix H to Subpart R, but engineering approval is a common and prudent control when altering member geometry.

• Why: notching or adding holes can create stress concentrations; engineer approval verifies the member will still meet design loads.

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)

Train erectors to follow the assembly sequence that maintains at least one bolt in the common member, to recognize clipped end and staggered hole details, and to report any fit-up or damage issues so they can use an approved alternate method. Appendix H illustrates the methods as guidance for complying with 1926.756(c)(1).

• Training elements:
  • Explain the safety objective of keeping one bolt connection at all times
  • Show clipped end and staggered connection examples from Appendix H
  • Practice proper bolting and visual inspection techniques
  • Emphasize engineer approval for any field modifications

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)

The official, non-mandatory illustrations and explanation of clipped end and staggered connections are in Appendix H to Subpart R — Double Connections, which is labeled "Non-Mandatory Guidelines for Complying With 1926.756(c)(1)." The appendix includes the two drawings that show a clipped end connection and a staggered connection.

(Reference: Appendix H to Subpart R and the relevant 1926.756(c)(1)).

The guidance in Appendix H is aimed at double connections where two members connect to a common member and the erector must make the connection without leaving the common member unsecured; it is not a universal rule for every steel connection. The goal is to satisfy 1926.756(c)(1), and Appendix H provides examples (clipped end and staggered) for that specific double-connection situation in Appendix H to Subpart R.

• If your connection scenario does not involve two incoming members to a common member during erection, Appendix H’s examples may not be directly applicable, but the general safety principle—avoid leaving members unsecured—still applies.

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)

An inspector should verify that the erectors maintained at least one bolt connection in the common member while installing the second incoming member, that the chosen method (clipped end, staggered holes, or an approved alternate) was implemented correctly, and that any notches or extra holes were engineered or approved. Appendix H shows typical clipped end and staggered arrangements to help assess compliance with 1926.756(c)(1).

• Specific inspection items:
  • Visual confirmation of at least one engaged bolt during the connection sequence
  • Correct fit of clipped end around opposing bolt head or nut, or correct alignment of staggered holes
  • Documentation of engineer approval for any modifications that affect strength

(Reference: Appendix H to Subpart R and 1926.756(c)(1).)