Shear Tab Connections: An Estimator's Guide

A shear tab — also called a single-plate connection — is a flat plate shop-welded to a column or girder web, with the incoming beam field-bolted to it through its web. It transfers vertical shear only, allows the beam end to rotate, and is the cheapest beam connection in steel construction. On a typical office or warehouse frame, shear tabs are 60-80% of all beam-to-column and beam-to-girder connections, so getting the count and unit cost right moves your bid more than almost any other connection line item.

If you can price a shear tab accurately at, say, $60-120 installed for a common 3-bolt configuration, and you can count every one on the drawings, you've handled most of the connection cost on a simple-framed job. This guide covers both halves: recognizing them, and pricing them.

What a Shear Tab Is and Where You'll See It

Mechanically, a shear tab is about as simple as connections get: one rectangular plate, one shop weld (usually fillet welds both sides of the plate to the support), and a single vertical row of bolts through the beam web. The beam flanges are not connected to anything, which is the whole point — no flange connection means no moment transfer, so the beam behaves as simply supported and the engineer's frame analysis stays clean.

You'll see shear tabs anywhere a beam frames into:

• A column flange — the most common case. Plate welded to the flange face, beam bolts on.
• A column web — the plate sticks out past the column flanges so the erector can get a wrench in.
• A girder web — infill beams framing into girders, usually with the beam top flange coped to clear the girder flange.
• An HSS column face — shear tabs are the default for tube columns because you can't bolt through a closed shape; the tab gets shop-welded to the tube wall.

Erectors like them because there's nothing loose: the plate arrives welded on, the beam swings in, bolts go through, done. No double angles to fumble, no loose fill plates on most jobs. That erection speed is a real part of why they're cheap.

How Shear Tabs Appear on Framing Plans and Details

Here's the estimating trap: shear tabs almost never appear on the framing plan. The plan shows beam marks and sizes — W16X26, W18X35 — and the connections live elsewhere. You'll find them in three places:

1. Typical details. Most jobs have a "TYPICAL BEAM TO COLUMN CONNECTION" or "TYP. SHEAR TAB DETAIL" on the S-500 series sheets. One detail, applied to hundreds of locations. The detail gives you plate size, weld size, bolt diameter and count — often as a table keyed to beam depth.
2. General notes. Language like "ALL BEAM CONNECTIONS SHALL BE SINGLE PLATE SHEAR CONNECTIONS PER AISC UNLESS NOTED OTHERWISE" or "CONNECTIONS TO BE DESIGNED BY FABRICATOR FOR REACTIONS SHOWN." That second one means connection design is on you (or your connection engineer) — budget for it.
3. Connection schedules. Some engineers tabulate it: beam depth in one column, number of bolts and plate length in the next. A W12 gets 3 bolts, W16 gets 4, W21 gets 5, W24 gets 6.

Callouts to watch for on details: "PL 3/8 x 4 x 0'-9"" (the tab itself), "3-3/4"Ø A325-N" (bolt count, diameter, spec), a fillet weld symbol with "1/4" or "5/16" both sides, and "STD" or "SSLT" hole callouts (short-slotted horizontal holes are common in tabs to give erection tolerance).

If the drawings say "connection design by fabricator," the plan will show end reactions (e.g., "R = 32K") or a note like "DESIGN FOR 50% UDL." Either way, the count still comes from the framing plan: every beam end that isn't a moment connection or a brace point is almost certainly a shear tab.

Typical Plate Sizes, Bolt Counts, and Materials

Conventional single-plate connections follow a tight pattern. Bolts at 3" vertical spacing, 1-1/4" edge distances, plate width 4"-5", and a bolt count that tracks beam depth. Typical configurations:

| Beam depth | Bolts (single row) | Plate size (typ.) | Weld (both sides) | Bolt spec (typ.) | |---|---|---|---|---| | W8-W10 | 2 | PL 1/4-3/8 x 4 x 0'-6" | 3/16"-1/4" fillet | 3/4"Ø A325-N | | W12-W14 | 3 | PL 3/8 x 4 x 0'-9" | 1/4" fillet | 3/4"Ø A325-N | | W16 | 4 | PL 3/8 x 4-1/2 x 1'-0" | 1/4" fillet | 3/4"Ø A325-N | | W18 | 4-5 | PL 3/8 x 4-1/2 x 1'-3" | 1/4"-5/16" fillet | 3/4"-7/8"Ø A325 | | W21 | 5 | PL 3/8-1/2 x 5 x 1'-3" | 5/16" fillet | 7/8"Ø A325-N | | W24 | 6 | PL 1/2 x 5 x 1'-6" | 5/16" fillet | 7/8"Ø A325 or A490 | | W27-W30 | 7-8 | PL 1/2 x 5 x 1'-9"+ | 5/16"-3/8" fillet | 7/8"-1"Ø A325/A490 |

Plate material is A36 or A572 Gr. 50. Bolts are overwhelmingly A325 (now technically F3125 Gr. A325, but every drawing still says A325), bearing-type with threads included ("N"). A490 shows up when reactions get heavy on deep beams. Tension-control (TC) bolts cost a bit more per assembly but install faster with one worker — many erectors insist on them.

Budgetary bolt assembly costs (bolt + nut + washer), which match what we carry as defaults in SteelFlo's hardware catalog:

| Assembly | Cost each (budgetary) | |---|---| | A325 3/4" x 2" hex | $2.50 | | A325 3/4" x 3" hex | $2.85 | | A325 7/8" x 3" hex | $3.50 | | A325 TC 3/4" x 3" | $3.35 | | A325 TC 7/8" x 3" | $4.00 | | A490 7/8" x 3" hex | $4.20 | | A490 1" x 3" hex | $5.40 |

Hardware is trivial money per connection — $8-25 — but on a job with 400 shear tabs at 4 bolts each, that's 1,600 assemblies, and pricing 7/8" TC when you assumed 3/4" hex is a $1,000+ swing on hardware alone.

Shear Tab vs Clip Angle vs End Plate: Quick Decision Table

The three common simple (shear-only) connections do the same structural job. Which one shows up on your drawings affects your shop hours more than your material cost. Full comparison in our clip angle vs end plate breakdown; the short version:

| | Shear tab (single plate) | Double clip angle | Shear end plate | |---|---|---|---| | Pieces per connection | 1 plate | 2 angles | 1 plate | | Shop work | Weld plate to support | Bolt or weld angles to beam web | Weld plate to beam end | | Field work | Bolt beam web (1 row) | Bolt to support (2 rows) | Bolt to support | | Beam fabrication | Plain cut (cope if at girder) | Plain cut | Square cut, tight length tolerance | | Erection speed | Fastest | Slower (more bolts, loose pieces if shipped loose) | Fast, but no length adjustment | | Relative installed cost | 1.0x | 1.2-1.4x | 1.1-1.3x | | Where it wins | Default everywhere, HSS columns | Heavier reactions, some coped conditions | Beam-to-beam in some shops, UK/EU practice |

If the engineer left connection selection to the fabricator, most US shops default to shear tabs for exactly these reasons: fewest pieces, fewest holes, fastest erection. See the full connection types guide for how these fit alongside moment and braced connections.

Estimating Shear Tabs: Budgetary Cost Ranges and Labor Notes

A workable per-connection buildup for a typical 4-bolt tab (W16 beam, PL 3/8 x 4-1/2 x 1'-0"):

| Component | Quantity | Budgetary cost | |---|---|---| | Plate material (~6 lbs @ ~$0.60/lb) | 1 | $4 | | Cut + punch/drill 4 holes | shop | $8-15 | | Fit + weld to column (2 x 12" of 1/4" fillet) | shop | $25-45 | | Bolt assemblies (4 x A325 3/4" x 3") | 4 | $11 | | Field bolting labor | erection | $15-30 | | Total installed | | $65-105 |

Scale that: 2-bolt tabs run $45-75, 6-bolt tabs on W24s run $100-160, and anything with extended configuration (plate cantilevers past the column flange, common at column webs) adds stiffness checks and sometimes a thicker plate — call it 1.3-1.5x. Coped beam ends at girder connections add $20-40 per cope in shop labor and matter for another reason: the cope is on the beam, so it hits the beam line item, not the connection line item. Miss the copes and your beam shop hours are light even though your connection pricing was fine.

Rules of thumb that hold up on plan-and-spec work:

• Simple-framed jobs run 1.5-2.5 connection shop hours per ton; shear-tab-dominated jobs sit at the bottom of that range.
• Count beam ends, not beams. A 200-beam job has ~400 connections. Every end is a tab unless it's a moment connection, brace workpoint, or bearing seat.
• If connection design is delegated, add $2,500-8,000 for a connection engineer on mid-size jobs, or your PE's time.

For where shear tabs sit in the overall connection budget against moment connections and braces, see how much steel connections cost.

Counting Connections in a Takeoff Without Missing Details Pages

The count is where bids go wrong, because the information is split: quantity lives on the framing plan, configuration lives on the details sheets, and exceptions live in the general notes. Three habits prevent the classic misses:

1. Count beam ends off the plan, then subtract the exceptions. Highlight moment connections (they're flagged with solid triangles or "MC" marks) and brace points. Everything left is a shear connection.
2. Read every S-500 detail sheet before pricing a single connection. The typical detail sets your bolt diameter and weld size for the whole job. A jump from 3/4" to 7/8" bolts or 1/4" to 5/16" welds across 400 connections is real money.
3. Reconcile plan count vs. detail flags. If the plan shows 380 infill beam ends at girders and you counted 12 coped conditions, something's off — nearly all of them cope.

This is also where software earns its keep. SteelFlo reads every page of your PDF — plans, details, schedules — and puts a bounding box on every member label it finds, so the beam-end count comes from the actual drawing rather than a highlighter pass, and connection detection flags bolt patterns and connection callouts from the details pages you might otherwise skim. Every detection sits on the drawing for you to confirm or reject, which is how the 95-99% accuracy figure works: AI detection plus your verification, not a black box. It covers 4,500+ steel sections across 6 international standards, so the W-shapes, HSS columns, and plate callouts all resolve to real sections with real weights.

Try connection detection on your drawings free. Upload a real project — you get 3 free takeoffs, no card required — and see what SteelFlo finds on your framing plans and details pages before your next connection-heavy bid. Start a free takeoff, and if it becomes part of your workflow, SteelFlo Pro is $399/month, flat.