Steel: section weights, light-gauge framing, baseplates, connections and member checks

What the steel calculators cover

Steel is counted by weight, which is how it is handled and delivered, and by member, which is how it is connected and checked. The weight pages turn a section's dimensions into a weight per unit length for hollow sections, pipe, angle, channel, I-beam, plate, bracing rod and reinforcing bar, and the tonnage page and the conversion pair add those up. The framing pages count light-gauge studs, track and screws, purlin rows and deck supports. The baseplate and connection pages count anchor bolts and bolts in a group, size a grout pocket and check a weld.

A last set of pages checks one figure against a published method: block shear and net section on a plate, baseplate bearing on concrete, the unbraced length limit of a girder, the capacity of a concrete-filled column, the deflection of a stud or a deck, and the shear of a castellated beam. They show a number to compare with the design; they do not size the member.

How the answers are worked out

Weight is area times density. The I-beam, tube, pipe, angle, channel and plate pages build the cross-section from the dimensions you enter and multiply by the density of steel, so a section whose designation omits its weight, such as an imported, cold-formed or custom channel or an angle, can still be weighed. The I-beam page says its simplified area omits the fillets and so slightly underestimates the published AISC tables.

Counts follow the layout. Purlin rows and deck supports are the run divided by the maximum spacing, rounded up, plus one, because a row of members is counted at both ends; studs are counted with both end studs; anchor bolts are counted along each side from the plate dimension less twice the edge distance, and the pitch to set out from is that run divided by one less than the bolts on the side, which is at or below the maximum entered and is not the maximum itself.

The checks cite named documents. Weld strength follows AISC 360 Section J2.4, the unbraced length limit its Chapter F, composite columns its Chapter I, and bolt shear, bearing and tearout its Chapter J. Baseplate bearing and anchor strength follow ACI 318, bolt torque follows RCSC and ASTM F3125 with a nut factor for plain, as-received hardware, and a light-gauge stud's effective section follows AISI S100. The deck deflection page uses the Steel Deck Institute relation and takes the effective moment of inertia from the deck maker's span table, since it cannot be derived from a general formula. The castellated beam page calls its shear check a starting-point screening and names the further checks that full design requires.

Units and documents by market

The market setting chooses the system the answers appear in: pounds, feet and short tons for the United States, kilograms, metres and tonnes for the other three markets, each answer restated in the other system. The weight pages use the same steel density in every market. The connection and member checks are written to American documents, AISC 360 and ACI 318, and the plate block shear page is the one place that names steel grades from both series, ASTM A572, A992 and A36 beside S355 to EN 10025.

Rounding, rows and whole pieces

Counts of rows, supports, holes and bolts round up, and add one where a run of equal spaces needs a member at each end. The stair stringer page counts bolt holes the same way from the stringer length and a maximum spacing, the moment connection page rounds the bolts up from the equivalent force over the rated capacity of one bolt, and the stud page counts studs and track separately. A weight is a net figure; the tonnage page multiplies a total length by a weight per unit length and converts it to tonnes.

Where to start

Start from the question. If it is an order or a lift, start with the weight pages, then the tonnage, then the conversion pair. If it is a wall or a roof, start with the framing pages: studs and track, purlin rows, deck supports. If it is a column or a beam, start with the baseplate and anchors, then the connection, then the member check, and finish with the coating that protects it, primer from the surface area and intumescent coating from a target dry film thickness.

What the calculators leave to others

A design value is an input, not a built-in table: the grade of steel, the rated capacity of a bolt or an anchor, the effective moment of inertia of a deck. The moment connection page uses a simplified bolt force from the moment and the lever arm, and the camber page says that standard fabrication practice cambers a beam to offset a specified fraction of its calculated dead-load deflection. The structural member pages leave the member, the connection and the detailing to the engineer.

Reference tables

• Production rates by operation

  How long each operation takes one person, in person-hours per unit of work.

Guides

The practice behind the numbers: how the work is done, what goes wrong and how to check it.

• Taking Off a Steel Package for Tender

  A frame drawing gives you lengths, not weights, and never gives you area. How to close both columns on the afternoon before the return goes in.

• Weighing Steel Sections

  An imported angle or a cold-formed C states its geometry and nothing else. Measure it, get kilograms per metre, and defend the tonne on the quote.

• Bolted and Welded Steel Connections

  A load-path field guide to steel joints: every bolt, weld, plate and stiffener a force must cross to leave one member and enter the next.

• Setting Steel Columns and Baseplates

  How a steel column is set true at the top where it buckles and bedded solid at the bottom where it crushes, from anchor layout through final grout.

• Installing a Steel Beam

  A steel beam almost never fails in strength — it fails the ceiling underneath, so deflection limits and bearing movement govern the whole install.

• Detailing a Steel Bracing Bay

  Sizing the diagonal in a braced bay, then proving the gusset it lands on will not tear out before the rod itself has yielded.

• Fire Protecting Steel to Its Section Factor

  The period is a property of the building and the thickness is a property of the member. How to build the section factor column the applicator is waiting on.

• Spacing Purlins and Deck Supports

  Secondary framing set out so purlin rows, deck spans and sheet end laps land on frame lines the primary steel order fixed weeks ago.

• Building a Steel Mezzanine Deck

  A whole structure squeezed into one bay of a running warehouse: slab, grid, deck span, bolt group and edge, in the order each one bites.

• Framing a Cold-Formed Steel Partition

  A tall steel partition decided the way it fails: section against the movement limit first, then the fastener counts that fall out of it.

Terms

• Structural steel grade
• Steel beam designations
• Anchor and fixing
• Plinth and toe kick
• Padstone and bearing plate
• Stud and framed partition

How the numbers are worked out

Every calculator names the method it uses and the standard or guidance behind it. These are the methods the most of the calculators above rest on, and the published documents they cite.

Methods

• Mass from Volume and Density

  Why a rolled steel section's mass is read from a table rather than computed, why one material has five densities, and why a tonne of wet sand is less sand. Applies to 9 of the calculators above.

• Fastener Capacity and the Failure Mode That Governs

  Why an anchor's capacity is the smallest of several modes rather than one number, why concrete breakout grows with embedment to the power of one and a half, and why hole cleaning is the largest variable on site. Applies to 4 of the calculators above.

• Fastener Schedules, Supports and Counting Over a Grid

  Why a fixing count is never area divided by spacing, why the edges of a panel supply more fasteners than its middle, and why the tighter schedule at a roof corner is a requirement rather than caution. Applies to 4 of the calculators above.

• Deflection, Creep and Vibration: What Governs a Span

  Why doubling a span multiplies its deflection by sixteen, why a stronger grade of steel does nothing for it, and why a floor that passes every deflection check can still be unacceptable to walk on. Applies to 3 of the calculators above.

• Section Capacity: Bending, Axial, Shear, and Which One Gives First

  Why depth is worth four times what width is in bending, why reinforced concrete is deliberately designed to fail in the steel rather than the concrete, and why a notch removes far more strength than material. Applies to 3 of the calculators above.

• Spacing, Pitch and the Count That Follows

  Why a run divided by a spacing gives the number of gaps and not the number of things, why the division rounds up rather than to nearest, and what the leftover bay at the end does to both. Applies to 3 of the calculators above.

Standards cited

• AISC 360

  Cited by 5 of the calculators above.

• ACI 318

  Cited by 2 of the calculators above.

• ASTM A615

  Cited by 1 of the calculators above.

• International Building Code

  United States. Cited by 1 of the calculators above.