Metal Fabrication Quoting Software for Custom Fabricators (2026 Guide)

If you have quoted a fabrication job from a public bid package, you have probably lost one to a price you could not explain. Before you shop for metal fabrication quoting software, look at two bid results that show why this happens.

In November 2023, the U.S. Army Corps of Engineers opened bids for eight steel trash racks for McNary Dam on the Columbia River. Six fabricators bid on the exact same drawings. The lowest bid was $227,000 and the highest was $1,353,736, which is six times as much.

In 2026, Gwinnett County in Georgia bought four stainless steel slide gates for a drinking water plant. Five companies bid, and the highest bid was twice the lowest.

Every bidder had the same pages, so the steel was never the difference. The difference sits in the words of the specification, and in the decisions each bidder made while reading them.

I build quoting software for fabricators who work from documents like these. This guide is what I wish every estimator had before choosing a tool: what each kind of software can price, what a custom fabrication bid package really asks for, and where the money hides.

Everything below comes from four public bid packages. You can download each one and check every page I cite.

Who this guide is for

There are two very different kinds of fabrication work, and they need different software.

Shops that quote parts

Some fabricators quote parts. A customer sends a 3D model or a flat pattern of a bracket, a panel or a machined part, and the shop prices it from the shape and size.

Those shops quote dozens or hundreds of parts a week, and speed matters more than anything else. If that is your work, a CAD-based quoting tool is the right buy, and this guide will only help you understand why.

Shops that quote custom jobs from a bid package

Other fabricators build one-off products to a customer's specification. Think of trash racks and slide gates for dams and water plants, welded steel tanks, pedestrian bridges, hoppers, chutes and equipment frames.

Their jobs arrive as a bid package written by the customer's engineers. It holds a specification book, a set of drawings, a bid form and usually a few addenda that change earlier pages.

For these shops, counting the steel is the easy part. The hard part is finding every requirement that costs money, scattered across a hundred or more pages, before the bid is due. This guide is for them.

If your work sits closer to process equipment, our guide to quoting water and wastewater equipment covers the same problem for screens, pumps and clarifiers.

The kinds of metal fabrication quoting software

Every quote comes down to the same few things: material, shop hours, outside work such as galvanizing or painting, testing, freight and margin. Every kind of quoting software helps with those numbers.

What separates the tools is the input each one starts from. The input decides which fabricators a tool really fits.

CAD-based part quoting

Paperless Parts is the best-known example. You upload the customer's 3D model, and the software reads the shape and dimensions: the bends, the holes, the thickness and the flat size of a sheet metal part. It then prices from those details using your machine rates.

This is great for a laser and press brake shop. It has nothing to work with when the job arrives as a 150-page specification and a set of PDF drawings.

Quoting inside a shop management system

Shop systems such as ProShop, MIE Trak Pro and JobBOSS² include a quoting module. You build the quote from a routing, which is the list of steps a part goes through in your shop, with the material and hours at each step.

When the customer says yes, the quote becomes a work order. That works well for repeat work, because the routing already exists. For a one-off job, someone still has to read the package and decide what the routing should be.

Steel estimating

Tekla PowerFab is built for structural steel fabricators. It prices from a takeoff, which is a count of every piece on the drawings, either brought in from a 3D model or typed in by hand.

For a building frame with hundreds of members, the takeoff is most of the work, so a takeoff tool pays for itself. For a trash rack or a slide gate, the piece count is small and the price depends on other things.

The spreadsheet

Most custom fabricators actually quote in a costing workbook that a senior estimator built over many years. It bends to any job, which is why it survives. Its weakness is simple: a person still has to read every input out of the customer's documents.

If you are weighing a configurator against a workbook, our page on CPQ for manufacturing walks through that choice in more detail.

What a custom fabrication bid package contains

A public bid package for a fabricated product usually has five parts. Each one can move the price, and they rarely mention each other.

• The solicitation or invitation to bid sets the commercial terms: payment, delivery, bonds, the certificates a bidder must hold and how the buyer evaluates the bid.
• The bid form or bid schedule lists what you are pricing, often as a single line for the whole job.
• The specification book holds the technical sections: materials, welding, coatings, testing and submittals. On public work it often runs to well over a hundred pages.
• The drawings show the product, and their general notes often add requirements that the specification does not repeat.
• The addenda change all of the above while the bid is open, sometimes a few days before it closes.

The McNary trash rack package is a good example of the scale. It has a 34-page solicitation, a 150-page technical specification and 23 drawing sheets, and the bid form is a single line: one set, at a firm fixed price.

The Gwinnett slide gate package shows how much the addenda can change. The first invitation asked for cast-iron slide gates. Eleven days later, Addendum 1 replaced them with fabricated stainless steel gates, which is a different product with a different price base.

Trash racks for McNary Dam: six bids from $227,000 to $1.35 million

A trash rack is a heavy steel grid that sits in front of a dam's water intake and stops logs and debris from reaching the turbines. The McNary job, solicitation W912EF24B0005, asked for one set for one generating unit.

One set is eight racks: seven intermediate racks and one bottom rack. Each rack is a welded grid of steel bars, about 21 feet wide and 12 and a half feet tall. The fabricator builds, paints and delivers them, and the Corps installs them.

We cannot know each bidder's reasons. What we can do is read the package and count the decisions it leaves to the bidder. There are a lot of them.

The job starts on site, not in the shop

The drawings tell the fabricator to check every control dimension in the field before making shop drawings. The specification asks the fabricator to measure six guide slots from the top of the intake deck, and to measure the old racks in the dam's maintenance yard too.

So before you cut any steel, someone has to travel to the dam, write a measuring plan, get it approved and submit a report. That trip is a priced line, and a bidder who skims the drawings can miss it.

The paint is a system of its own

You have to paint the racks with the Corps' own vinyl system, called 5-E-Z on the drawings. It is not a simple coat of primer and a coat of enamel.

• The steel gets a white metal blast, which is the most thorough grade of blast cleaning, with no rust or mill scale left anywhere.
• Then you apply a zinc-rich primer and three vinyl coats, and the schedule calls for each coat to go on as a double spray coat.
• You may not use airless spray equipment for the vinyl paints.
• The finished film must average at least 7.0 mils, with no spot under 5.5 mils.
• The Corps' lab tests every batch of paint, and the specification says to allow at least 30 days for sampling and testing.

Each of those lines adds hours, and the 30-day paint test adds time to a schedule that already runs a full year.

Who may paint: a sentence on page 4 against a sentence on page 137

This is the clearest conflict in the package, and it could decide where you paint the racks.

The solicitation accepts either certificate. The specification accepts only one. A shop that holds the AISC coating endorsement but not SSPC QP 3 can read page 4 and paint in its own shop.

A shop that reads page 137 has to send every rack out to a certified paint shop, which means a subcontract, a markup, and trucking every rack to the paint shop and back. The same job carries two very different paint prices depending on which page the estimator trusted.

Welding that a Corps inspector watches

The drawings call for welding to AWS D1.1-2020, which is the structural welding code. The specification then sets how much of that welding gets tested.

• Every completed weld gets a visual inspection.
• Every full penetration weld gets ultrasonic or radiographic testing.
• A random quarter of the fillet and partial penetration welds get magnetic particle or dye penetrant testing, and any reject means you must test all of that weld.
• The welds on the lifting brackets and aligning weldments get magnetic particle testing in full.

A Government representative must be present for all of that testing, with 15 days' notice. Every test is therefore an appointment, and your schedule has to allow for the wait.

A shop with height, a roof and a full-time quality manager

The specification requires you to fabricate and assemble the racks in an indoor, climate-controlled shop. The contractor's quality control manager must be on site at all times during fabrication, including during the work of subcontractors.

Before shipping, you must hang each rack in the vertical position for a witnessed dimensional check, and you must stack two racks one on top of the other. Then you have to weigh every rack on a calibrated load cell. A shop without the hook height for two stacked racks has to find another way to run that test.

Small conflicts that still cost money

The package has several smaller disagreements. None of them is dramatic, but each one is a question someone has to answer.

• Drawing S-001 says the contacting surfaces of the bearing shoes must be parallel within 1/8 inch. Drawing S-502 says the bearing shoes are not critical dimensions, because they are where you adjust the fit.
• For the surfaces of bolted connections, the drawings say primer coat only, the paint schedule says zinc-rich primer, page 147 says friction connections are not painted, and page 122 asks for a rust-resisting compound.
• The drawings name one nut standard and the specification names another.
• Drawing note 1.8 asks the fabricator to list any missing welds it adds, and note 1.14 warns that the drawings may omit some components and features.

A year of steel and labour on a fixed price

Delivery is due 365 days after the contract date, and the solicitation includes the clause "Progress Payments Not Included". The fabricator buys the steel, builds and paints eight racks, and pays for all of it for a year before getting paid.

For a small shop, that financing cost alone can decide whether the job is worth bidding. It never appears on a drawing.

Here is one more useful number. The original drawing of the old racks, included as a reference sheet, carries a handwritten note: "Weight of One Trash Rack 12,923#". It is a good check on your own steel weight, and it is not on the new drawings.

Stainless slide gates for Gwinnett County: the product changed mid-bid

Gwinnett County's Department of Water Resources bought four 108-inch slide gates for the Lanier Filter Plant under bid BL044-26. A slide gate is a plate that slides up and down in a frame to open or close a water channel.

These gates are 9 feet square, built of Type 316L stainless steel, and the two high-head gates must hold back more than 41 feet of water from either side. The job is supply only, and the manufacturer designs the gates.

The bids fall into two groups, one near $450,000 and one near $870,000. For the two high-head gates alone, the unit prices ran from $115,367.95 to $281,057 each.

A cast-iron package that became a stainless one

The invitation of February 9, 2026 specified cast-iron slide gates. Addendum 1, on February 20, answered a bidder's question with this:

The same addendum said the buyer would not accept fiberglass and composite gates. So less than two weeks into the bid, every bidder had to price a different product.

Supply only, except where it isn't

Addendum 3 says plainly that the job is now supply only.

Yet the revised gate section in that same addendum still lists a "Manufacturer's Certificate of Proper Installation" and field performance test reports among the submittals. A certificate of proper installation usually means someone from the manufacturer visits the site. One bidder prices zero field days and another prices several trips.

Standards that point at the wrong product

• The scope of work says leakage must meet AWWA C560, which is the standard for cast-iron slide gates. The gate section sets its own limit of 0.1 gallon per minute per foot of gate perimeter, in both directions.
• The factory test paragraph asks the manufacturer to test each gate at its required seating and unseating head. A later line asks only for the manufacturer's standard test.
• Testing must follow AWWA C651, which is the standard for disinfecting water mains, not for testing gates.

A full test against 42 feet of head on a 9-foot gate needs a serious test rig. A standard cycle test does not. That one choice can explain a large part of the price spread.

Design you have to stamp

The gates must resist full water pressure on either side when the other side is drained. A professional engineer registered in Georgia must design the anchorage and bracing and seal the calculations. That is engineering time a bidder has to price before the gate exists.

Welded steel water tanks in Calaveras County: the warranty says 5 years, then 2

The Calaveras County Water District in California bid its Copper Cove tanks project in 2023. It includes two new welded steel water tanks built to AWWA D100, the standard for welded carbon steel water storage tanks.

This was a general construction bid, so the five bids from $6,929,450 to $9,866,210 cover the whole site, not just the tanks. The tank section is still a good lesson in reading closely.

The tank builder designs the tank and the foundation

Section 33 16 00 makes the contractor completely responsible for designing the tank, including the foundation, with the design signed by a California registered engineer employed by the tank manufacturer. A bidder asked whether they could use the alternative design basis in Section 14 of D100.

Addendum 2 also added a design snow load of 16 pounds per square foot after a bidder asked. Both answers change the steel in the tank.

Two warranty periods in two paragraphs

The very next paragraph schedules the warranty inspection "approximately 18 months after substantial completion and before expiration of 2-year warranty period". The contract also asks for a 2-year warranty bond worth 15 percent of the contract price.

Carrying a structural warranty for five years instead of two is a real cost, and the estimator has to decide which one the price carries.

Two coats or three, and two kinds of cathodic protection

• One paragraph of the coating section describes the interior as a two-coat epoxy system. A few paragraphs later, the interior system lists three coats for a total of 13 mils.
• The tank section refers to AWWA D104, which covers impressed-current cathodic protection with a rectifier and controls. The cathodic protection section and Addendum 2 describe passive galvanic anodes instead.
• The bid form describes the new clearwell as a 346,000 gallon tank, while the cathodic protection section lists a 360,000 gallon new clearwell.

An extra full coat over the floor, shell and roof underside of two tanks is a lot of paint and labour. A rectifier system costs more than magnesium anodes. Neither one shows up in a takeoff.

A steel truss footbridge for Colorado Springs: a 20,000-pound truck called HS-10

The City of Colorado Springs asked for quotes in October 2024, under RFQ Q24-133AL, for a 143-foot pedestrian truss bridge in weathering steel, 10 feet wide, for the Sand Creek Trail at Greenways Park. The supplier designs, fabricates and delivers the bridge.

The bridge fabricator's own engineer must sign and seal the shop drawings and calculations. So every requirement in the 38 pages shapes a design, not just a price.

A load that does not add up

In the AASHTO truck loadings, an H10 truck weighs 20,000 pounds. An HS10 truck adds a trailer axle and weighs 36,000 pounds. The floor beams, stringers and connections come out differently depending on which one the engineer designs for.

A warranty of 2 years on one page and 10 on another

Page 3 asks for "a two-year guarantee on all works performed under this contract". Page 5 asks for the bridge to be free of design, material and workmanship defects "for a period of 10 years from the date of delivery".

That is eight more years of design risk, counted from a different start date.

Delivery, unloading and installation

• Page 2 expects delivery on January 30, 2025, while page 3 allows 120 calendar days after the notice to proceed. Quotes were due on November 7, 2024, so the January date leaves little time for design, review, getting weathering steel from the mill and fabrication.
• Page 1 says the City will unload the bridge. Page 2 says the owner's contractor will unload it, and the supplier coordinates the equipment.
• Page 2 excludes installation and crane rental, yet the execution part of the specification still describes setting the bridge and placing the concrete deck.
• The two drawing sheets are stamped DRAFT, with an empty box where the engineer's stamp goes, and the fabricator must still supply the anchor bolts and templates for the abutments.
• The fabricator must hold an AISC certification in the category "Major Steel Bridges", a name AISC's current bridge categories no longer use, so a bidder has to ask which current category the City will accept.

A checklist: what to find in the words before you price

Across the four packages, the same kinds of requirements moved the price. Here they are in one place, with an example of each.

None of these is about geometry. A tool that only reads the drawing, or only reads a CAD file, cannot see any of them.

Our pre-bid risk assessment guide shows how to keep that list as a register you can send with the bid.

How AI quoting software prices a bid package

We built Mavlon's AI Quoting Engine for this exact job. It starts from the customer's bid package, not from a CAD file, a model or a catalogue.

What it does

• It learns how your shop prices from your costing workbooks, your rates and the quotes you have sent before. It does not bring a price list of its own.
• It reads each new package, including the solicitation, the specification, the drawings and the addenda, and it pulls out every requirement your price depends on, along with the page it came from.
• It prices those requirements your way and produces a draft quote with each line tied to its page.
• Where two pages disagree, such as the McNary painter rule, it carries the likely reading and prices the other one beside it, so the estimator can see what the choice is worth.
• Where the package does not settle something, the line says TBD instead of guessing, and the software writes out the questions for the buyer.

What it does not do

• It does not match part numbers to a catalogue or apply list-price discounts. It prices custom work from the customer's documents.
• It does not quote parts from CAD models. A sheet metal shop should buy a CAD-based tool.
• It does not do member-by-member takeoff for structural steel buildings. That is a different problem, and steel estimating tools are built for it.
• It does not design the product, approve anything for fabrication or set your margin, and it never sends anything to your customer. Your estimator checks the draft and decides the final number.

The AI quoting for custom metal fabricators page shows what that looks like for a fabrication shop, and our manufacturing quoting software guide compares every kind of tool across manufacturing.

How to test metal fabrication quoting software on your own jobs

A demo on someone else's example tells you very little. A fair test uses jobs your team has already priced.

1. Pick three to five past bid packages that you priced in full, along with the quote you sent. Include at least one job you lost and one you won.
2. Agree on the pass mark in writing before anything runs. For example, decide how close the totals must be and how many of your estimator's own flags the tool must find.
3. Run the packages without giving the tool your answers. It should only see what the buyer sent you.
4. Compare the results line by line, not only the totals. A right total built from wrong lines is luck, and it will not repeat.
5. Check every page reference. If the tool says a requirement comes from page 137, page 137 should say it.
6. Look at the questions it would have sent the buyer. Ask yourself whether they would have changed your price.

This is how we run our own pilot: we run it on your past packages, with the pass mark set before the first run, so you can compare the results with the prices you actually sent.

Whatever tool you choose, choose it for the input your work arrives in. If your jobs arrive as a CAD file, buy a CAD quoting tool. If they arrive as a bid package, buy something that reads the bid package.