Structural Steel Detailing Services for Fabricators and Erectors
Production detailing in Tekla Structures and SDS2: erection drawings, assembly and single part sheets, anchor rod setting plans, the advance bill of material and NC files for your beam line. Packages release by sequence against a dated calendar you can hold against your own mill lead times.
What a released sequence ships with
- Erection drawings with the piece marks in your numbering
- Assembly and single part sheets drawn for your shop floor
- Anchor rod setting plan with template and grid dimensions
- Advance bill of material your buyer can send to a mill
- DSTV NC1, DXF nests and a KISS export for your EPM system
Where detailing sits in the fabrication chain
Structural steel detailing services convert an engineer's design drawings into what a shop and a crew actually build from. We run Tekla Structures and SDS2 in house, and this is the chain the work sits inside.
Award, contract documents, shop standards signed
Advance bill of material, then the mill order
First round RFIs and connection resolution
Modeling, then a second detailer's check print
Submittal, the review window, and what comes back
Release for fabrication, then the field
The advance bill of material is the first deliverable
A steel job is won or lost at the mill order, and the mill order is written off the advance bill of material. It is the shortest document in the package and the most expensive one to get wrong.
An ABM is a purchase list, not a measurement exercise. Shape, grade, ordered length, quantity and the sequence each piece belongs to, written so a mill or a service center can quote it and roll it: W-shapes in A992, HSS in A500 Grade C, plate and angle in A36 or A572 Grade 50. Ordered lengths are chosen so the shop cuts two pieces out of one stick instead of buying two sticks and racking the drop.
Timing is the entire point of it. Domestic rolled sections carry roughly 6 to 12 week lead times and anything uncommon carries more, so the list has to leave inside the first week or two after award, long before one assembly sheet exists. Over-length, heavy and off-list sections get flagged at the top, because those come from one mill on one rolling cycle and missing that cycle costs weeks that no amount of shop overtime buys back.
What the list leaves out matters as much as what it carries. Shop stock stays off it, so your buyer does not order plate and angle already sitting on the rack. Camber is called out with its source, because a cambered beam ordered from the mill and a beam cambered in the shop are two different costs. ASTM A6 mill tolerances on sweep, camber and out of square get stated wherever the fit-up is tight enough to care about them.
This is also the one deliverable on this page that genuinely moves at estimating speed. An advance bill of material and a member schedule read off a structural set are a 24 to 96 hour job from an approved fixed quote. A full detailing package is not, and any shop quoting you a whole package in hours is quoting a set it has not opened.
What a steel shop drawing package actually contains
Structural steel shop drawing services produce two families of sheets for two audiences who never open the same page. The erector works off marks and plans, the shop works off dimensions and holes.
Erection drawings, the sheets the erector reads
Also called general arrangement, or GA.
Plans, elevations and the marks on them
GAEvery piece located and marked, with column lines, top of steel elevations, working points and the field connections called out at each joint. This is the sheet somebody reads in the wind with a radio in one hand.
Marks a crew can read from the ground
Piece marks follow your numbering scheme, in your prefix convention, at a size that survives a bad print. A mark that only makes sense inside the model has already cost somebody a walk back to the trailer.
Field bolt list by connection type
Bolt grade, diameter, length and quantity summarized by connection so the shipment includes the bolts the joints actually need. Shop bolts and field bolts are separated, because the crate and the shop bin are not the same order.
Sequence and shipping lot drawings
LOADSThe erection sequence drives the detailing sequence and the shipping lots, never the reverse. Lots are built around the crane and the laydown area, not around what happens to be modeled.
Loads built to the pick, not to the model tree
Maximum ship length, width and weight and the crane pick capacity are constraints on the model itself. A field splice added at detailing stage because the piece cannot be shipped is a design conversation, not a drafting decision, so it goes back as a question first.
Steel fabrication drawings, the sheets the shop reads
Assembly and single part, and the two are not interchangeable.
Assembly drawings
MAINOne fabricated member per sheet with every attached part located from a work point: clips, stiffeners, gussets, plates, holes, welds. This is what gets fitted and welded on the bench.
Dimensioned from work points, not from part edges
Working points and work lines carry the geometry so a fitter is never adding four tolerances together to place the last clip. Copes, blocks and weld access holes are dimensioned rather than left to the saw operator's judgment.
Single part drawings
PARTSOne cut piece per sheet, with every hole, bevel, cope and radius, ready for the burn table or the drill line. The shop cannot fabricate the assembly without them and the erector never sees them.
The sheet and the NC file have to agree
A single part drawing and the NC1 file for that part come out of the same model, and both are checked against the assembly. When the machine and the sheet disagree, the operator trusts the machine and nobody finds out until fit-up.
Connection details and weld symbols
JOINTSShear tabs, double and single angles, end plates, seated connections, moment connections, braced frame gussets, HSS joints and base plates, drawn with AWS A2.4 symbols against AWS D1.1 requirements.
A legal symbol your shop hates still costs hours
A weld symbol can be correct and still be wrong for your floor: the wrong side of the reference line for how you fixture, a CJP where a PJP was always going to be accepted, a fillet sized past what a single pass carries. Your preferences come off the standards sheet, which is why it gets signed first.
Steel joist and metal deck detailing, and where the package stops
The scopes that arrive as somebody else's submittal.
Joists and joist girders
SJIJoists are designed and detailed by the joist manufacturer to SJI standards. What this desk owns is the interface: bearing seats, seat depths, bearing plates, stabilizer plates, bridging anchorage into the frame and the top of steel that has to reconcile between two submittals.
Metal deck
SDIDeck is laid out and supplied against SDI conventions, composite or form deck by the specification. The detailing question is the support: edge angles, pour stops, closures, deck support at openings, and the shear studs whose spacing has to miss the flange holes somebody else put there.
What is not in a steel package
BOUNDARYMeasured quantities for a bid are a different product on a different desk. Nothing in a detailing package is a substitute for a measured set of quantities, and detailing rates are a bad way to buy one.
Anchor rod setting plans, the anchor bolt plan that ships first
AISC says anchor rod and the shop still says anchor bolt. Either way it is the first drawing off this desk, it goes out weeks ahead of the steel, and it is the only sheet whose mistake gets buried in concrete.
A setting plan is drawn for a concrete crew, not for an ironworker. It carries the rod layout under every base plate, the projection above top of concrete, the embedment the engineer specified, the template dimensions and the column line each group is dimensioned from. Issued early it is one sheet and one review. Issued late it is a change order against a foundation that is already formed, and sometimes already poured.
The tolerances are tight enough to be worth writing down. AISC 303 sets placement at 1/8 in. center to center between any two rods inside a group and 1/4 in. between adjacent groups. That is what a concrete crew is being asked to hold with rebar in the way. An anchor rod hole is not a bolt hole: the AISC anchor rod hole table puts a 1 5/16 in. hole under a 3/4 in. rod, with a plate washer over it, because the slack has to live somewhere.
When rods do land out of position, every remedy is expensive. Ream the base plate hole out and weld a plate washer over it all round. A doubler plate. Cutting the rods and setting epoxy anchors, which needs the engineer's approval and a fresh set of calculations. Or the column goes up out of position and drags the frame with it, which nobody notices until the third bay will not close. The cheap fix is a setting plan checked against the column grid before the pour.
Two conflicts turn up on almost every job and neither is drawn on the structural sheets. The rod group fights the pier reinforcing, and the leveling nut and grout space fight the finished floor elevation. Both are cheap questions before the pour and expensive ones after it, which is the entire argument for getting this one sheet out ahead of everything else in the package.
Whose standards the drawings follow, captured before anything is modeled
Steel detailing for fabricators goes wrong on the first two jobs for one reason: the detailer detailed to their own habits. This is the intake sheet, and no piece gets modeled until it comes back signed.
Send one sequence before you send a job
One sequence, one stair, one misc metals package. The price is agreed in writing first, and the drawings, the production files and the model on request come over whether or not there is a second one.
Where connection design stops and detailing starts
Connection design coordination and connection design are two different jobs, and a detailer who blurs them costs you a rejected submittal. Here is the line, written where you can hold us to it.
Who designs the connections on your job?
AISC 303 gives three routes. The engineer shows the connections complete on the design drawings; or the engineer gives the forces and a licensed engineer working for the fabricator completes them; or the fabricator's engineer designs them to stated criteria. Which route applies is a contract question, answered before modeling starts rather than during it.
Do you seal or stamp connection design?
No. This desk does not employ a licensed professional engineer, does not seal connection design and is not the engineer of record. Delegated connection design has to be sealed by an engineer licensed in the project state. What happens here is coordination: the engineer's forces and details get modeled, checked, and questioned where they do not close.
What happens when the drawings give no connection forces?
It becomes the first RFI, with a schedule attached rather than a paragraph. Missing forces are the most common hole in a structural set and they are worth catching in week one instead of week six. Affected members are listed with blank force columns, so the engineer fills in one table instead of answering forty separate questions.
Does an approved shop drawing move the risk to the engineer?
No. Approval says your interpretation of the contract documents is accepted. It does not hand responsibility for a detail dimension, a hole location or a member fit back to the engineer, and it never has. A stamp on a sheet has yet to weld a shear tab onto the correct side of a web.
What else is outside this desk's scope?
Connection design and any engineering seal. Erection engineering, lift plans and temporary bracing design. Special inspection and testing. Delegated design of stair and rail systems where the specification demands a sealed submittal. Every item on that list needs a licensed engineer, and you should hire one rather than be told it was included.
When should you keep the detailing in house?
Whenever your board has float, keep it: a thirty ton job of familiar framing is faster in house than briefing it out. If all you need is the mill order away, buy the advance bill of material alone and draw the rest yourself. A model abandoned at sixty percent costs more inherited than restarted, and we say so before quoting.
The AISC 303 submittal clock, and the four return statuses
The submittal clock is the part of a steel schedule nobody controls and everybody blames. Here is how it runs, what each return status costs you, and where a second review cycle comes from.
| Approved | Your reading of the contract documents is accepted | Nothing. Release the sequence and cut steel |
|---|---|---|
| Approved as Noted | Accepted, with corrections to work in before release | Hours. Notes get modeled in, no resubmittal |
| Revise and Resubmit | Rejected in part, and back through the full review | A second review window on top of the redraw |
| Rejected | The submittal does not represent the design intent | The sequence restarts, usually behind an RFI |
| Returned late, or not at all | The window in the specification has quietly passed | Your detailing float, while the mill date holds |
The checker is a different person, and here is the list
A package that has only been self-checked has not been checked. The detailer who modeled the sequence checks it, then a second detailer who never touched it back-checks the package on a check print against this list.
Ask before you send a drawing set
Which seats we run, who checks the package, whether your controller is covered. Ask for the free NC file test along with the question and a matched DSTV file comes back before you commit.
CNC and EPM output, DSTV NC1, DXF nests and KISS
The file format is not the deliverable. A DSTV file your beam line will not read, or reads with the holes a millimeter out, stops the machine exactly as hard as no file at all.
Tekla steel detailing services, and what leaves with you
The model, the drawings and the reference files, handed over.
The Tekla model
DB1The .db1 model comes over on request, not held back as leverage. Tekla opens forward only, so the version is agreed at the quote rather than discovered at handover, and a seat one release behind cannot open what a newer seat produced.
Version agreed before modeling starts
Name the release your seat runs and the job is modeled in it. This is a two minute conversation at quote stage and a two week problem at handover, because there is no downgrade path: the only way back is a fresh model or an IFC that has already dropped the joints.
IFC is a fallback, not a handover
IFC 2x3 and IFC 4 both carry geometry and both lose connection intelligence: bolts, welds and the logic that made the joint. An IFC file is right for coordination with the architect and wrong as your record model.
SDS2 detailing services
SDS2SDS2 runs here as well, and the choice follows your shop rather than our preference. If your EPM, your machines and your existing connection library are built around SDS2, that is what the job gets modeled in.
Advance Steel, and what we do not run
HONESTNo Advance Steel seat here. If your existing model is authored in it, say so at quote stage and you get a straight answer about whether the job is a fit, before you commit rather than after the first sequence is late.
Production files for the machines on your floor
Named machines, not a format list.
DSTV NC1 for the beam and drill line
NC1The .nc1 files come out mapped to the machine you name. Peddinghaus, Voortman and Ficep controllers do not all take an identical file, and a post processor nobody tested is how a beam line spends a morning idle.
Post processor matched to the machine by name
Tell us the machine and the controller, not just the brand. Hole types, marking, scribing and cope conventions differ between lines from the same manufacturer, and the difference shows up as a rejected file rather than as a warning.
DXF nests for the plate table
DXFPlate parts come out as DXF for the burn table, unfolded where the part is bent, with the bend allowance stated rather than assumed. Gusset, base plate and bent plate geometry gets checked against the assembly before it nests.
KISS into your EPM system
KISSA KISS export drops the bill of material straight into Tekla EPM, StruMIS or FabTrol so nobody retypes a mark list. Retyped marks are the quiet source of the mismatch between what the shop built and what the erector is expecting.
Prove the output before you commit to anything
One part, one file, one hour on your own machine.
The NC file test, at no cost
FREESend one part you have already run, the single part drawing or the .nc1 your own line was fed, and name the machine and the controller on it. A matched DSTV NC1 comes back free. Load it, or diff it against the file you already hold, and you know inside an hour whether this output drives your line. No quote, no obligation, no sales call attached to it.
Miscellaneous metals detailing, and the code stack behind stairs
Miscellaneous metals is where steel packages leak. Embeds, lintels, kickers and stair headers sit between two subcontracts, and the rulebook behind a stair is thicker than the one behind the frame.
Miscellaneous metals shop drawings, and the pieces that get orphaned
05 12 00 on one side of the seam, 05 50 00 on the other.
Where the seam actually sits
05 12 / 05 50Structural steel framing is 05 12 00, joists 05 21 00, decking 05 31 00. Metal fabrications start at 05 50 00. The specification draws that line in words, the subcontracts draw it in money, and the two lines are almost never in the same place.
The usual orphans
ORPHANSThe same handful of pieces goes missing on job after job, because each one is drawn on a sheet belonging to a trade that is not buying it.
Embeds and loose lintels
Embed plates are drawn by structural, installed by concrete and fabricated by steel, so all three assume somebody else has them. Loose lintels sit on masonry elevations and never appear on a framing plan at all.
Kickers, stair headers and railing posts
Wall kickers appear on architectural sections. Stair headers appear when the stair supplier asks for them. Railing post baseplates and their anchors appear when someone tries to install a rail into a slab edge nobody reinforced for it.
Steel stair and railing shop drawings
05 51 00, 05 52 00 and 05 53 00, drawn as their own package.
Stairs
05 51 00Stringers, treads, risers, landing framing, hangers and the connections back into the frame, plus the field dimensions that have to be verified before anything is cut.
The pan stair that has to hold a poured tread
A pan stair is drawn for concrete that arrives later: pan depth, reinforcement, the nosing detail and the deflection of a stringer supporting wet weight. Get the pan depth wrong and every finished tread height in the flight is out.
Railings and guards
05 52 00Posts, top rails, infill, wall returns and the anchorage. The anchorage is where it goes wrong: a guard designed for a 200 lb concentrated load bolted to a slab edge with no embed and no reinforcement behind it.
Gratings, floor plate and access
05 53 00Bar grating, checker plate, hatches, ladders, cages and platform framing. The detailing question is nearly always support spacing against a deflection limit, and where the grating gets banded around a penetration.
The code stack behind a stair
Three rulebooks, and they do not agree with each other.
IBC geometry, where the public uses it
IBCRisers 7 in. maximum and 4 in. minimum, treads 11 in. minimum, headroom 80 in. off the nosing line, guards at 42 in., handrails 34 to 38 in., and a 4 in. sphere through the guard infill. Guards and handrails carry 50 plf and a 200 lb concentrated load.
OSHA, where the stair is industrial
OSHADifferent numbers entirely: 1910.25 for stairways, 1910.23 for fixed ladders, 1910.29 for the guardrail and handrail criteria. Riser and tread limits, an angle band, and stair rail height measured off the tread nosing. A plant platform stair drawn to IBC numbers fails an OSHA walk.
ADA, where accessibility applies
ADAHandrail extensions 12 in. horizontal beyond the top riser and one tread depth at the slope beyond the bottom riser nosing, graspable sections between 1 1/4 in. and 2 in., continuity around landings. The extension is the one that hits a wall the architect drew tight to the flight.
When the drawn geometry does not comply
RFIIt goes back as an RFI with the arithmetic attached and two options priced. A detailer who quietly redraws the stair to comply has changed the architect's design without authority. A detailer who models exactly what is drawn has fabricated a stair that fails inspection. Neither of those is a service.
AESS categories and galvanizing, what each does to the drawings
Two specification notes change the model rather than the paint shop: an AESS category, and a hot dip galvanizing requirement. Both get written by somebody who will not be in the room when the drawings are produced.
AESS detailing is a modeling decision, not a finishing one
AISC 303 sets out AESS categories 1 through 4 plus Custom, and the category has to be identified in the model before fabrication, not discovered at paint. Which members are exposed, which faces are seen and from what distance all change how the piece gets built. Exposed frames, canopies and lobby steel carry this far more often than plants do.
Tolerances at roughly half of standard
At the higher categories fabrication tolerances tighten to around half of standard, welds get ground and filled, and a mock up is built and approved before production runs. That is a different shop rate, a different drawing and a different review cycle, and it belongs in the quote before the job is booked rather than in a claim afterwards.
Vent and drain holes that were never on the design drawings
A hot dip galvanized member needs zinc to get in and air to get out. Vent and drain holes get located and sized by the detailer, on the drawing, following ASTM A385 practice, in places the engineer never drew and the architect would rather not see. Plant steel, pipe rack framing, platforms and grating carry this note far more often than a conditioned building does.
A galvanized faying surface is not automatically Class A
The RCSC specification does not let a hot dip galvanized faying surface count as Class A until it has been roughened after galvanizing. If a joint is slip critical and the member is galvanized, the drawing has to say what happens to that surface, or the field finds out with a torque wrench and a rejected inspection.
Where shop primer stops and field work starts
Faying surfaces, members due for sprayed fireproofing, embedded surfaces and the top flange under composite deck all get masked or left bare, and every one of those boundaries is a drawing instruction. Get it wrong and fireproofing debonds or shear studs get welded through paint.
The detailing calendar, mapped onto mill and fabrication dates
This is a calendar, not a claim about speed. Put your own mill lead time and your own erection start against it and the honest answer about a detailing date falls out of the arithmetic.
Shop standards signed, erection sequence agreed
Advance bill of material to your buyer
Steel detailing turnaround time is a sequence release date
Approval review, and a resubmittal if it comes
Release for fabrication, NC output, shop floor
Steel detailing services for erectors, after release
Capacity for a full award, not one sequence
A whole award is six or eight sequences released against one calendar, not one order. On a monthly partnership your sequences hold priority in that calendar and the standards sheet is agreed once, not per job.
RFI response in US hours, and the revision split by cause
Two things decide whether an outside detailer costs or saves: how fast a question gets answered, and who pays when a drawing turns out wrong. Both are written down before the job starts.
When will somebody actually answer an RFI?
In US business hours, by a named detailer on your job, not a ticket queue and not a shared inbox. Messages get a reply within 30 minutes during the working day. The offshore rate stops looking cheap the second a fitter's question waits overnight for a shift that has gone home. Chasing the engineer's answer is our work too.
What does a well formed RFI from a detailer look like?
One question, one subject. The sheet and detail it comes from, the members affected, what was assumed in the meantime so modeling could continue, and the schedule consequence of a late answer. Numbered, logged, and closed in writing when it is answered. An engineer answers that in minutes. A vague one sits for a week.
If the drawing turns out wrong, who pays to fix it?
Split by cause, in writing, before the job starts. Our error is corrected at no charge and on the fastest clock available, corrected sheets and files included. A design change, an owner scope change or a sequence change after release is priced and quoted before any work starts, never added to an invoice afterwards.
How are revisions tracked once sheets are out?
R0, R1 and R2 on the sheet, clouds and revision triangles around what moved, and the superseded issue kept rather than overwritten. The RFI log, the submittal log and the drawing issue record reconcile against each other. Continuity is a document problem here, not a staffing one: whoever picks the job up can say which issue the shop cut from.
Our model and shop standards are competitive assets. What protects them?
An NDA signed on request before a file changes hands, named against your fabrication model, your connection library and your standards sheet rather than written as boilerplate. Your files are used for your work and nothing else. Nothing from your job is published, shown to another fabricator or used as a sample.
How steel detailing is priced, and what a paid pilot covers
Fabricators outsource steel detailing when the award and the queue collide, and they buy it on three or four bases that each punish a different kind of job. Here is what each rewards, what it costs you, and what gets quoted instead.
| Per ton | Heavy repetitive frames with simple shear tabs | Light frames, connection heavy work, misc metals |
|---|---|---|
| Per sheet | Simple sheets, and a lot of them | Dense sheets, and anybody who details efficiently |
| Per hour | The detailer, on every job, always | The buyer, who cannot budget before the invoice |
| Per piece | Long simple members with little attached | Stairs, rails and anything with parts on it |
| Fixed quote per sequence | The buyer, who has the number before work starts | Us, on the job where the set was read too fast |
Steel detailing questions, answered straight
What fabricators and erectors ask before they hand a structural set to an outside detailer.
The basics
The ABM and the mill
Scope and responsibility
Buying it
Send the structural set and get a
sequence calendar
Name the fabricator, the erection sequence and the machines on your floor. A fixed price, a first submittal date and a release interval come back in writing before a single piece is modeled.