Steel detailing software: Tekla, SDS2 and steel estimating
Steel detailing software builds a 3D model of structural and miscellaneous steel, designs or applies connections, and generates fabrication-ready shop and erection drawings, bills of materials and CNC data for the shop. Two established platforms are Trimble's Tekla Structures and ALLPLAN's SDS213. Estimating is a separate step: tools like Tekla PowerFab and Steel Genie (from the SDS2 team, $9,950 per license) take off and price steel for the bid54 before any detailing starts.
What a steel takeoff measures
| Item | Unit | What to watch |
|---|---|---|
| Beams, columns and braces | Pieces by shape, LF, TON | Weight by shape and length is the base of a steel estimate. Detailing later adds exact cut lengths and copes. |
| Connections | EA by type | Shear tabs, moment connections, base plates and brace gussets drive shop hours more than tonnage does. Count them by type for the estimate. |
| Plates and miscellaneous metals | LB and EA | Embed plates, lintels, ledger angles and support frames, often scattered across architectural and structural sheets. |
| Stairs and rails | EA flights, LF rail | Usually a separate package with its own detailing and shop labor. |
| Bolts and welds | EA bolts, LF weld | Bolt counts by size and grade, and field versus shop welds, affect both shop and erection cost. |
| Deck and joists | SF deck, EA joists | Often purchased from a manufacturer, but the takeoff still belongs in the steel bid. |
How a steel estimate is built
- Estimate first: take off members by shape and length from the structural drawings, count connections by type, and price material, shop hours, coatings and erection.
- Once the job is won, set up the detailing model with grids, levels and the project's connection and fabrication standards.
- Model members, then apply or design connections, checking the engineer's reactions and the fabricator's preferred details.
- Clash-check against other trades and resolve RFIs with the engineer of record before releasing drawings.
- Generate shop drawings, erection drawings, bills of materials and NC files, and send drawings for approval.
- Manage revisions in the model so drawings, BOMs and CNC data update together, and feed fabrication management for nesting, purchasing and production.
What to look for in steel software
Parametric connections
Most detailing time goes into connections. Look for a large library of parametric or automatically designed connections that match your shop's standards.
Drawings and revisions from the model
Shop and erection drawings, BOMs and schedules should regenerate from the model when something changes, with revision tracking.
Shop data output
NC and DSTV-style data that drives saws, drill lines and plate machines saves rekeying in the shop. Confirm the formats your machines need.
Hand-off to fabrication management and estimating
The estimate, model and shop systems should share data so estimated weight, detailed weight and shipped weight can be compared.
Software steel estimators use
| Tool | What it does for steel | Price |
|---|---|---|
| Tekla Structures Trimble | Constructible structural BIM for engineers, detailers, fabricators and contractors. For steel detailing it provides parametric tools and pre-configured components, one-click fabrication-ready drawings with automatic revision management, BOMs and reports, and production data that drives CNC machinery.12 | Not published (three subscription options; 30-day free trial) |
| SDS2 ALLPLAN | Detailing and modeling software for structural and miscellaneous steel, stairs and rails and steel connections, with connection design and integrations with office and shop systems. Offered as SDS2 Ultimate, Modeling, Drafting and Basic.3 | Not published |
| Steel Genie ALLPLAN (SDS2) | AI steel takeoff and estimating for structural steel fabricators and estimators, going from structural drawings to steel estimates and exporting an IFC model.4 | $9,950 per license |
| Tekla PowerFab Trimble | Steel fabrication management with an estimating program for bids, plus project management, nesting, purchasing, inventory and production control.5 | Not published |
As described on each vendor's own pages, checked November 3, 2026. Prices change; check with the vendor.
For tools that cover every trade on one plan set, see the construction takeoff software and construction estimating software guides.
What is Tekla software?
When people search for Tekla software they almost always mean Tekla Structures, Trimble's structural BIM application. Trimble describes it as constructible BIM software for structural engineers, designers, detailers, fabricators, contractors and project managers, and it is used for both steel and concrete, including rebar detailing1. It is sold as subscription plans with three material-independent options, each paired with Trimble Connect Business Premium and Tekla Model Sharing, and Trimble offers a 30-day free trial1.
Tekla is also a family name. Tekla PowerFab is fabrication management (estimating, purchasing, nesting, production)5, and the family also includes Tekla Structural Designer and Tekla Model Sharing, which Trimble describes as a collaboration platform1. For a steel fabricator, the usual pairing is Tekla Structures for detailing and PowerFab for running the shop, though many shops mix Tekla or SDS2 with other estimating and production tools.
Steel detailing software vs steel estimating software
Detailing happens after award and produces what the shop builds from. Estimating happens before award and has to be fast, because fabricators bid many more jobs than they win. That is why vendors sell them separately: Steel Genie and Tekla PowerFab's estimating module price the job from drawings45, while Tekla Structures and SDS2 model it once the job is real23.
Building steel in the grounding system and as a support for electrical work
Structural steel is part of the electrical design whether the detailer models it that way or not. In the 2020 NEC text, metal in-ground support structures in direct contact with the earth vertically for 10 feet or more, such as pilings and casings, qualify as grounding electrodes6. The 2023 text of 250.68(C)(2) lets the steel frame serve as a conductor between electrodes, and lets the hold-down bolts on a column connect the frame to a concrete-encased electrode in its footing, joined by welding, exothermic welding, tie wire or other approved means7. If the engineer relies on that path, the anchor bolt and footing details carry an electrical requirement the fabricator should see before shop drawings go out.
The bigger money question is supports. Strut racks for conduit, platforms for transformers, frames for rooftop units and kickers for heavy fixtures are misc metals on some jobs and electrical scope on others, and holes or welded grounding lugs in beams usually need the engineer's approval either way. Frames under rooftop HVAC equipment and racking attachments for a rooftop solar array are the usual places two bids both assume the other carries the steel.
Write the split into the misc metals and electrical proposals line by line. Most commercial electrical estimating software carries strut and hanger assemblies by the foot, so the electrical side can price its share once it knows the fixture count. AmpCount supplies that count from the electrical sheets; it does not detail or price steel.
Where steel takeoffs go wrong
- Estimating by tonnage alone. Two jobs with the same tonnage can have very different connection counts and shop hours.
- Miscellaneous metals scattered through architectural sheets (lintels, ladders, supports) missed because the takeoff only covered structural sheets.
- Detailing before RFIs are answered, then reworking drawings after the engineer changes connections.
- Revisions handled outside the model, so drawings and BOMs drift out of sync with what the shop is cutting.
- Confusing detailing software with estimating software and expecting a modeling tool to produce a bid on day one.
Trades that bid the same job
A steel bid rarely stands alone. The trades next to it on the schedule read the same drawings and often share scope lines, so it pays to know how they take off too: metal building estimating software, rebar estimating software, concrete estimating software and masonry estimating software.
Where AmpCount fits
AmpCount only counts electrical devices and fixtures, so it does not detail, model or estimate structural steel. The trades meet in coordination: fixture supports, unistrut and equipment frames are sometimes misc metals and sometimes electrical scope, and the electrical contractor can count the fixtures and devices those supports carry with AmpCount.
Questions
What is the most used steel detailing software?
Tekla Structures and SDS2 are two established platforms for structural steel detailing23. Vendors do not publish comparable usage numbers, so evaluate on connection libraries, drawing output and the CNC formats your shop needs.
Is Tekla free?
No. Trimble sells Tekla Structures as subscription plans and offers a 30-day free trial1. Prices are not published on the product page.
Can steel detailing software estimate a job?
A detailing model can produce accurate weights and BOMs, but building a full model to bid is slow. Many fabricators estimate in dedicated tools such as Tekla PowerFab or Steel Genie54 and detail only after award.
How much does Steel Genie cost?
The SDS2 site lists Steel Genie at $9,950 per license, checked November 20264.
Does Tekla do concrete and rebar too?
Yes. Trimble describes Tekla Structures as material-independent, and its customers include concrete builders and reinforcement suppliers1. See the rebar estimating software page for the estimating side.
Guides and tools for any trade
Sources
- Tekla Structures product page (Trimble)
- Tekla steel detailing solution page (Trimble)
- SDS2 steel detailing software home page (ALLPLAN)
- Steel Genie by ALLPLAN: AI steel takeoff and estimating
- Tekla PowerFab steel fabrication management (Trimble)
- ElectricalLicenseRenewal.com, NEC 250.52 electrodes permitted for grounding (quotes the 2020 text)
- ElectricalLicenseRenewal.com, NEC 250.68(C) grounding electrode conductor connections (quotes the 2023 text)
Product names are trademarks of their owners. AmpCount is not affiliated with any vendor on this page.