Bolted Connection Checklist

Checklist for reviewing bolted connection calculations: geometry, holes, detailing, failure modes, and documentation.

Bolted connections are among the most common elements in steel design, yet they are also where small input mistakes create the largest discrepancies. A wrong hole type, an overlooked edge distance, or a mismatch between factored and service loads can shift a utilization ratio by 20-40% without any obvious warning in the output.

This checklist is organized around the inputs and assumptions that matter most for bolted connections. It is written as a documentation and QA aid, not as engineering advice. The goal is to help you catch errors before they reach a calculation note or a fabrication drawing.

For the full general verification workflow (units, replication strategy, sensitivity testing, and archiving), see How to verify calculator results.

Before You Start

Collect these inputs before running any bolted connection calculator:

Connection demands: Factored shear Vu, tension Tu, and any moment Mu at the connection interface. Know the governing load combination and whether demands are LRFD (factored) or ASD (service).
Bolt specification: Diameter, grade (A325/A490/F3125, 8.8/10.9, Grade 4.6/8.8), threads included or excluded from the shear plane, and installation method (snug-tight, pretensioned, or slip-critical).
Hole type: Standard, oversize, short-slotted, or long-slotted. This directly affects net area, bearing capacity, and slip-critical design. Confirm the hole type matches the fabrication drawing.
Connection geometry: Number of bolts, rows, columns, vertical spacing (pitch), horizontal spacing (gage), edge distances (top, bottom, and side), and plate thickness(es).
Material grades: Plate and connected member yield and ultimate strengths (e.g., A36: Fy = 36 ksi, Fu = 58 ksi; A992: Fy = 50 ksi, Fu = 65 ksi).
Connection type: Simple shear (shear tab, clip angle, end plate) or moment connection (extended end plate, flange plate). This determines which limit states apply.

Step-by-Step Design Process

Step 1 — Define geometry and detailing. Lay out the bolt pattern. Check minimum pitch (2-2/3 d, preferred 3d per AISC J3.3), minimum edge distance (AISC Table J3.4), maximum edge distance (lesser of 12t or 6 in per AISC J3.5), and maximum pitch (lesser of 24t or 12 in for painted members). Record hole type and deduction.

Step 2 — Compute bolt shear capacity. Per AISC 360-22 Table J3.2: phi Rn = phi x Fnv x Ab per bolt, where phi = 0.75. For A325-N (threads included): Fnv = 54 ksi. For A325-X (threads excluded): Fnv = 68 ksi. Multiply by the number of bolts and the number of shear planes.

Step 3 — Check bearing and tear-out. Per AISC J3.10, bearing strength per bolt: phi rn = phi x 2.4 x d x t x Fu (deformation considered) or phi x 3.0 x d x t x Fu (deformation not considered). Tear-out per bolt: phi rn = phi x 1.2 x Lc x t x Fu, where Lc is the clear distance from the hole edge to the plate edge or adjacent hole edge.

Step 4 — Check net section rupture. Compute the net area An using the effective hole diameter (actual hole + 1/16 in per AISC B4.3). For staggered holes, apply the s^2/(4g) correction. The net section capacity: phi Pn = phi x Fu x Ae, where phi = 0.75 and Ae = U x An (U is the shear lag factor from AISC Table D3.1).

Step 5 — Check block shear. Identify the block shear failure path (shear along bolt line + tension across top or bottom). Per AISC J4.3: phi Rn = phi x (0.6 Fu Anv + Ubs Fu Ant) <= phi x (0.6 Fy Agv + Ubs Fu Ant). The Ubs factor is 1.0 for uniform tension stress, 0.5 for non-uniform.

Step 6 — Check slip-critical (if applicable). Per AISC J3.8: phi Rn = mu x Du x hf x Tb x ns per bolt, where phi = 1.0 (serviceability) or 0.85 (strength). Class A faying surface: mu = 0.30. Class B: mu = 0.50. Du = 1.13 for standard installation.

Step 7 — Document all checks. Record which limit states were checked, which governs, and the utilization ratio for each.

Worked Example

Given: Simple shear connection (shear tab) transferring Vu = 60 kips from a W21x44 beam to a W14x61 column. Three 7/8-in A325-N bolts in standard holes, 3-in vertical spacing, 1.5-in edge distance. Shear tab: PL 3/8 x 4.5 x 10.5, A36 (Fy = 36 ksi, Fu = 58 ksi).

Step 1 — Detailing check:

Minimum pitch: 2-2/3 x 0.875 = 2.33 in. Provided 3.0 in. OK.
Minimum edge distance (sheared edge, 7/8 bolt): 1-1/2 in per AISC Table J3.4. Provided 1.5 in. OK.
Standard hole diameter: 15/16 in. Effective hole for net area: 15/16 + 1/16 = 1.0 in.

Step 2 — Bolt shear:

Ab = pi x 0.875^2 / 4 = 0.601 in^2
phi rn = 0.75 x 54 x 0.601 = 24.3 kips/bolt
Total: 3 x 24.3 = 73.0 kips > 60 kips. OK (ratio = 0.82).

Step 3 — Bearing on tab:

phi rn = 0.75 x 2.4 x 0.875 x 0.375 x 58 = 34.3 kips/bolt
Tear-out (bottom bolt, Lc = 1.5 - 15/32 = 1.03 in): phi rn = 0.75 x 1.2 x 1.03 x 0.375 x 58 = 20.2 kips
Governing per bolt = min(34.3, 20.2) = 20.2 kips (bottom bolt)
Interior bolts Lc = 3.0 - 15/16 = 2.06 in: phi rn = 0.75 x 1.2 x 2.06 x 0.375 x 58 = 40.4 kips > 34.3 kips, so bearing governs at 34.3 kips
Total = 20.2 + 2 x 34.3 = 88.8 kips > 60 kips. OK.

Step 4 — Block shear:

Agv = 0.375 x (1.5 + 2 x 3.0) = 0.375 x 7.5 = 2.81 in^2
Anv = 0.375 x (7.5 - 2.5 x 1.0) = 0.375 x 5.0 = 1.875 in^2
Ant = 0.375 x (1.5 - 0.5 x 1.0) = 0.375 x 1.0 = 0.375 in^2
phi Rn = 0.75 x (0.6 x 58 x 1.875 + 1.0 x 58 x 0.375) = 0.75 x (65.25 + 21.75) = 65.3 kips > 60 kips. OK (ratio = 0.92).

Governing check: Block shear at 0.92 utilization.

Common Pitfalls

Hole deduction error. AISC B4.3 requires adding 1/16 in to the actual hole diameter for net area calculations (to account for punching damage). For a 7/8-in bolt in a standard 15/16-in hole, the effective deduction is 1.0 in, not 15/16 in. This is the single most common discrepancy between hand checks and software.
Threads included vs excluded. A325-N (threads in shear plane): Fnv = 54 ksi. A325-X (threads excluded): Fnv = 68 ksi. Using the wrong value changes bolt shear capacity by 26%. Verify the connection detail shows which condition applies.
Ignoring tear-out at edge bolts. Bearing capacity assumes sufficient clear distance. When the bolt is close to a plate edge, tear-out (1.2 Lc t Fu) governs over bearing (2.4 d t Fu) and can cut the per-bolt capacity by 40-50%.
Forgetting block shear. Block shear often governs for connections with few bolts or bolts close to plate edges. It is a separate limit state from net section rupture and must always be checked.
Mixing LRFD and ASD demands. Entering ASD (service-level) demands into an LRFD calculator or vice versa. This error shifts the utilization ratio by the load factor (typically 1.5x).
Ignoring prying action in tension connections. When bolts carry tension (e.g., T-stub or end plate connections), the plate flexibility can amplify the bolt tension by 20-40% through prying action per AISC Part 9.

Code Comparison

Design Aspect	AISC 360-22	AS 4100-2020	EN 1993-1-8	CSA S16-19
Bolt shear phi	0.75	0.80	gamma_M2 = 1.25	0.80
Bearing phi	0.75	0.90	gamma_M2 = 1.25	0.80
Net section phi	0.75	0.85 (rupture)	gamma_M2 = 1.25	0.75
Hole deduction	d_hole + 1/16 in	d_hole + 2 mm	d_hole (no addition for punched holes ≤ 25mm)	d_hole + 2 mm
Bearing formula	2.4 d t Fu (deformation)	3.2 d t fu (per bolt)	2.5 d t fu / gamma_M2	3.0 d t Fu
Block shear	0.6 Fu Anv + Ubs Fu Ant	0.6 fy Agv + fu Ant	Similar approach per Cl. 3.10.2	0.6 Fu An + Ubs Fy Ag
Slip-critical (Class A)	mu = 0.30, phi = 1.0 or 0.85	mu = 0.35, phi = 0.70	mu = 0.20, gamma_M3 = 1.25	mu = 0.30, phi = 0.82
Tension-shear interaction	(ft/phi Fnt')^2 + (fv/phi Fnv)^2 <= 1.0 (modified)	Linear (Vf/phi Vf + Ntf/phi Ntf <= 1.0)	(Fv/Fv,Rd)^2 + (Ft/Ft,Rd)^2 <= 1.0	Elliptical interaction

Geometry & detailing

Bolt diameter, grade/class, and installation method are defined (and consistent with procurement).
Hole type is explicitly stated (standard/oversize/slotted) and matches the detail.
Edge distances, pitch, and gage are recorded and checked against minimum detailing rules.
Plate thickness and any cope/notch geometry that affects net section are captured.
Maximum edge distance and maximum pitch limits are checked (these are easy to overlook).
For multi-row patterns, confirm the bolt count and row layout match the intended configuration.

Demand definition

Shear and tension demands are defined at the connection interface (and not double-counted).
Eccentricity assumptions are explicit (e.g., load applied through centroid vs offset).
Confirm whether demands are factored (LRFD/Limit States) or service-level (ASD/Working Stress).

Failure modes (ensure you at least consider them)

Bolt shear and/or bolt tension (as applicable).
Plate bearing and tear-out (detail-dependent, requires clear distance calculations).
Net section rupture and block shear/tearing paths.
Group effects and load distribution assumptions (especially for large bolt groups).
Shear-tension interaction (when both are present simultaneously).
Slip-critical checks (if specified — note the faying surface class matters).

Documentation

State which checks were evaluated by the calculator and which were not.
Record the governing standard and edition (e.g., AISC 360-22 LRFD, AS 4100-2020).
Keep a screenshot or exported report with inputs and outputs.
Archive the calculation with a date stamp so results can be reproduced later.

Frequently Asked Questions

What is the most common error in bolted connection calculations? Hole type mismatch. Using standard hole deductions when the detail calls for oversize or slotted holes changes net area and bearing calculations significantly.

Should I check both bearing and slip-critical? If the connection is specified as slip-critical, the slip check governs serviceability. Bearing and shear checks still apply as ultimate limit states. Both should be documented.

Why does the calculator show different results than my hand check? The most frequent causes are: different hole deduction conventions, different clear distance formulas for tear-out, or a mismatch between threads-included vs threads-excluded shear capacity. Check these before assuming either result is wrong.

Does this checklist apply to all bolt standards? It is standard-agnostic. The items apply whether you are working with AISC 360, AS 4100, EN 1993-1-8, or CSA S16, but the specific factor values and detailing limits differ by code.

Is this checklist engineering advice? No. It is a documentation and QA pattern to help reduce errors and improve traceability. Project criteria and compliance decisions are defined by the governing standard and the engineer of record.

What is the standard hole diameter for a 7/8-inch A325 bolt per AISC Table J3.3, and how does it affect net area calculations? Per AISC 360-22 Table J3.3, the standard hole diameter for a 7/8-inch bolt is 15/16 inch (0.9375 in). For net area calculations per AISC Section B4.3, an additional 1/16 inch is deducted to account for damage during punching, giving an effective hole diameter of 1-1/16 inch (1.0625 in) for net area calculations — even though the actual hole is only 15/16 inch. For an oversize hole (1-1/16 inch actual), the effective deduction becomes 1-3/16 inch. This 1/16-inch damage allowance is a common source of discrepancy between hand checks and calculator outputs.

What minimum pitch and minimum edge distance apply to 3/4-inch bolts in standard holes per AISC? Per AISC 360-22 Section J3.3, the minimum center-to-center pitch is 2-2/3 × d_b = 2.0 inches for 3/4-inch bolts, but 3 × d_b = 2.25 inches is preferred. Per AISC Table J3.4, the minimum edge distance for a 3/4-inch bolt to a sheared edge is 1-1/4 inches and to a rolled/gas-cut edge is 1 inch. The absolute minimum clear distance for bearing (J3.10) is 1.5 × d_b = 1.125 inches from the hole edge to the material edge, measured in the direction of force. Maximum edge distance per J3.5 is the lesser of 12t or 6 inches (for unpainted members in contact), where t is the thickness of the connected element.

Run This Calculation

→ Bolted Connection Calculator — bolt shear, bearing, tension, and block shear checks per AISC 360, AS 4100, EN 1993, and CSA S16.

→ Gusset Plate Calculator — gusset plate and weld design for bracing connections.

→ Splice Connection Calculator — beam and column splice bolt group design.

Disclaimer (educational use only)

This page is provided for general technical information and educational use only. It does not constitute professional engineering advice, a design service, or a substitute for an independent review by a qualified structural engineer. Any calculations, outputs, examples, and workflows discussed here are simplified descriptions intended to support understanding and preliminary estimation.

All real-world structural design depends on project-specific factors (loads, combinations, stability, detailing, fabrication, erection, tolerances, site conditions, and the governing standard and project specification). You are responsible for verifying inputs, validating results with an independent method, checking constructability and code compliance, and obtaining professional sign-off where required.

The site operator provides the content "as is" and "as available" without warranties of any kind. To the maximum extent permitted by law, the operator disclaims liability for any loss or damage arising from the use of, or reliance on, this page or any linked tools.