Guided member review
SteelBox opens the right sheet and focuses the next unresolved member. No hunting through drawings.
SteelBox by PencilHB · Free demo available
Structural drawings in.
Structural drawings in.
Reviewed steel takeoff out.
SteelBox is structural steel takeoff software with AI drawing review, built by PencilHB for steel teams. It finds the steel members on your drawings, helps you measure and group them, and shows the evidence behind every suggestion. You confirm each decision.
3 drawings free · Google sign-in · No credit card
- Finds members, section labels and marks
- Measures and groups them with you
- Nothing is final until an engineer confirms it
0Members found
0Confirmed by you
0Waiting for review
Built forSteel estimatorsFabricatorsStructural engineersDetailersContractors & preconstruction
NewAgentic drawing intelligence
Watch AI work directly on the drawing.
SteelBox now guides itself through structural drawings. The agent moves to the drawing evidence, prepares scale calibration, proposes member measurements and brings each decision to the engineer for confirmation.
AI moves. You verify. Engineering stays in your control.
Auto-guided measurement
From drawing to confirmed measurement.
- 01
Calibrate
SteelBox focuses on a known dimension on the drawing, traces it and prepares the scale calibration for your confirmation.
AgentFinds and traces the dimensionYouConfirm the scale - 02
Measure
The agent scans the sheet, marks the structural members it recognizes and prepares a measurement proposal for each one.
AgentDetects members, prepares lengthsYouNo searching sheet by sheet - 03
Review
The Auto Cursor takes you straight to each member and shows its member ID, section and proposed length on the drawing.
AgentFocuses and traces the memberYouCheck the evidence in place - 04
Confirm
Drag the start or end point if the length needs adjusting, then confirm. The agent moves on to the next engineering decision.
AgentAdvances to the next memberYouAdjust and confirm
AI proposes.
Engineers confirm.
SteelBox automates the repetitive movement through complex structural drawings without hiding the engineering evidence behind a black box. Every calibration and every member length stays a proposal until an engineer confirms it.
The agent handles navigation, detection and measurement proposals for structural steel takeoff. Engineers keep the decisions, and professional review is still required.
The problem
Steel takeoff is mostly searching.
Before anyone makes an engineering decision, hours go into finding members, matching labels and copying numbers between drawings and spreadsheets.
Today 7 manual steps
- Find the member
- Find the right sheet
- Read the section label
- Search for the mark
- Measure it
- Type it into a spreadsheet
- Find similar members
↻ Repeat for every member on every sheet
With SteelBox 4 steps
- SteelBox shows the next member
- The evidence is on screen
- You decide
- SteelBox moves on
Less time searching. More time on engineering decisions.
How it works
Six steps from drawing to takeoff.
SteelBox does the repetitive work. Every step that changes your numbers waits for you.
Step 01 · Upload drawings
SteelBoxReads every sheet: linework, text and section labels.
YouChoose the drawing set you want to review.
Step 02 · Find & organize
SteelBoxFinds members, reads section labels and marks, and groups them by section.
YouNothing yet. This is the searching you no longer do by hand.
Step 03 · Calibrate
SteelBoxGuides you to a clear, known dimension on the sheet.
YouClick its two ends and confirm the value to set the scale.
Step 04 · Review each member
SteelBoxOpens the right sheet, focuses the next unresolved member and shows its evidence.
YouConfirm, edit, reject or skip. Then SteelBox moves on.
Step 05 · Measure & group
SteelBoxFinds same-section members that could share a length.
YouApprove which ones do. Same section does not mean same length, and manual values are never overwritten.
Step 06 · Takeoff & BOM
| Mark | Section | Length | Weight | Status |
|---|---|---|---|---|
| B2-01 | W16×26 | 25'-0" | 650 lb | Confirmed |
| G2-01 | W18×35 | 30'-0" | 1,050 lb | Confirmed |
| C-A1 | W12×53 | 28'-0" | 1,484 lb | Confirmed |
| VB-01 | HSS6×6×3/8 | 28'-8" | 788 lb | Confirmed |
| Example total | 3,972 lb | |||
SteelBoxCollects reviewed members, lengths and sections for takeoff and BOM.
YouDo the final review. The takeoff and BOM workflow is under active development.
Free demo
Try SteelBox on your own structural drawings
Upload a drawing, review detected steel members, calibrate the sheet, check measurements and move toward a reviewed takeoff.
Try 3 Drawings Free
No credit card required · Google sign-in
Live demo
Try the review yourself.
Rotate the frame, click any member, then confirm it or ask for the next unresolved one. This is how review in SteelBox feels: one clear decision at a time.
Drag to rotate · Click a member
Ready to test it on your own drawing?
The frame above is an illustration. The button opens the real SteelBox workspace: create a free account and test up to 3 structural drawings.
Try SteelBox Free
3 drawings free · Google sign-in · No credit card
AI + you
AI proposes. Only you approve.
Every AI suggestion stops at an approval gate. Nothing becomes project data until an engineer accepts it.
DrawingsYour structural sheets
AI suggestsMembers, labels, marks, missing items
Evidence shownSource region and confidence
You decideAccept · Edit · Reject
Project dataConfirmed and traceable
AI suggestion
B2-07 is a W16×26
- Source
- Sheet S-201, grid 2, B–C
- Confidence
- 0.82 (example)
- Why review
- Label partly crossed by a leader line
Try it: you are the approval gate.
What AI does
- Reads drawings and finds evidence
- Suggests missing members, marks and sections
- Links each suggestion to its source region
- Puts the most important reviews first
What stays with you
- Calibration and confirmed measurements
- Which members form a group
- Applying lengths across a group
- Final confirmation of every member
Capabilities
Structural steel takeoff software built around your review.
Drawing-first workspace
The drawing stays big. Panels collapse, and zoom, fit and pan keep the context in view.
Calibrated measurement
Set the scale once, then measure point to point. No AI-generated dimension is trusted silently.
Smart grouping
Measure one member and apply it to approved similar members. Conflicts are protected.
AI evidence
Every suggestion links back to its source region, with confidence and context you can inspect.
Traceable takeoff
Reviewed members move toward takeoff and BOM with auditable decisions behind them.
Who it's for
Built for the teams behind structural steel.
Get from a drawing set to reviewed quantities with less searching. See SteelBox for structural steel estimating.
Check member lists against the drawings before planning work.
Review members with the drawing evidence in view.
Find marks, sections and missing members across sheets.
Understand the steel scope earlier in preconstruction.
Structural steel takeoffMember review & recoveryDrawing measurementMember groupingDrawing QAFabrication estimating support
SteelBox finds. SteelBox focuses. SteelBox suggests. The engineer decides.
Automation should remove searching, not engineering judgment.
FAQ
Common questions
Is SteelBox fully automatic?
No. SteelBox is AI steel takeoff software, not an automatic one. It automates the searching, navigation and evidence gathering. Engineers confirm members, measurements and groups. AI suggestions never become project data on their own.
Who is SteelBox for?
Structural steel estimators, fabricators, detailers, structural engineers and preconstruction teams who review structural drawings.
Can I try SteelBox today?
Yes. Create a free SteelBox demo account with Google and test up to 3 structural drawings. The product is still actively evolving, so engineering review remains required.
How much does SteelBox cost?
You can try up to 3 structural drawings free in the SteelBox demo. Commercial pricing is not public yet. For team, pilot or production use, contact mail@pencilhb.com.
Does SteelBox replace professional engineering review?
No. Quantities and engineering decisions still need review by qualified professionals against the drawings, specifications and applicable standards.
Want the manual method first? Read how to do a structural steel takeoff from drawings or browse all guides. Estimators can read how SteelBox fits the estimating workflow.
For teams and commercial pilots
Need SteelBox for your team?
The free demo is for trying the workflow. For larger drawing volumes, team evaluations or commercial pilots, talk directly with the SteelBox team.
Spend less time searching drawings.
Spend more time making engineering decisions.
See how AI-guided drawing review can move your steel workflow toward takeoff, with you in control. Read how a takeoff runs in SteelBox.
Need real-world image or video data for your AI?
PencilHB Data runs managed field collection on construction sites, in workshops and in warehouses, including egocentric and multi-view capture.