Projection welding cost per accepted part = total expected batch cost ÷ expected accepted parts. Build the batch total from material, setup, labor, machine time, power, electrodes, inspection, scrap, rework, tooling, packaging, and overhead. Then apply either markup on cost or a gross-margin formula to set the selling price. This guide shows each step and a worked $2.10-per-part example.

Last updated: August 10, 2026

What Is Projection Welding, and Why Does It Affect Cost?

Projection welding is a resistance-welding process. A raised projection on one part concentrates current and electrode force at a planned joint location. The projection heats and collapses during the weld schedule, allowing a joint to form while force is maintained.

AMADA Weld Tech’s resistance-welding guidance identifies electrode force, squeeze time, weld pulse, and hold time as central parts of the weld schedule. It also explains that projections focus current and force into a small area.

Common uses include weld nuts, weld bolts, brackets, electrical parts, rings, crossed wires, and automotive assemblies. The process can be used for sheet metal and some thicker weldments when the part design, machine capacity, current path, and projection geometry are suitable.

If the job is conventional resistance spot welding rather than a formed-projection joint, use the spot welding cost calculation guide. The cost drivers overlap, but projection geometry, multi-projection loading, and part-level yield change how the quote should be structured.

Projection design affects contact resistance, current density, collapse, indentation, expulsion, and joint strength. Multi-projection parts also require even projection height, stable force, good alignment, and balanced current flow. One projection that contacts early can take more current than the others.

A fast weld cycle does not automatically create a low-cost part. Loading, setup, inspection, electrode care, downtime, and rejected output may cost more than the electrical weld pulse itself.

What Should You Gather Before Costing Projection Welding?

Collect the job details before building the cost model. A quote is only as reliable as its drawings, rates, production assumptions, and acceptance criteria.

Planning estimate: A basic quote often takes 30 to 90 minutes when the required records are available. A new or safety-critical part may need trials, fixture design, weld-schedule development, destructive testing, and customer approval before a dependable production cost can be set.

• Current drawing revision, material grade, thickness, coating, and tolerance details
• Purchased blank, stamped part, fastener, insert, and packaging prices
• Welds or projections per part and parts per machine cycle
• Started quantity, expected accepted quantity, batch size, and annual volume
• Machine model, input power, transformer rating, weld schedule, and expected duty cycle
• Squeeze, weld, hold, load, unload, inspection, and electrode-dressing times
• Fixture, gauge, programming, electrode, cooling, and maintenance requirements
• Required pull, push-off, peel, torque, sectioning, dimensional, or process-monitoring checks
• Loaded labor rate, machine-hour rate, overhead method, and target markup or gross margin
• Customer terms for tooling ownership, freight, packaging, payment, and price validity

When a contract, drawing, or customer specification calls for an industry standard, confirm the exact edition before quoting. The AWS C1 Committee currently lists AWS C1.4M/C1.4:2025 for resistance welding of carbon and low-alloy steels.

How Do You Calculate Projection Welding Cost?

The most useful master formula is based on accepted output:

Projection welding cost per good part = total expected batch cost ÷ expected accepted parts

Total expected batch cost may include:

Material + setup + production labor + machine time + energy + consumables + tooling + inspection + destructive samples + expected rework + scrap + packaging + allocated overhead

Define the denominator before calculating the numerator:

• Started parts: Every part loaded into the process, including later rejects
• Accepted parts: Parts expected to pass final requirements
• Final yield: Accepted parts ÷ started parts
• Weld unit: The unit used for quoting, such as one weld, one part, one assembly, or one batch

If every accepted part receives the same number of welds, accepted welds = accepted parts × welds per part. For a weld-only quote, use cost per accepted weld = weld-attributable batch cost ÷ accepted welds. Keep whole-part costs such as base material, packaging, and part-level scrap at the part level unless your accounting method intentionally allocates them per weld.

For example, a batch of 1,000 started parts at a 97% final yield is expected to produce 970 accepted parts. Fixed setup, qualification, and tooling costs should therefore be divided by 970, not 1,000.

Selling Price Formulas

Markup and gross margin are different:

• Selling price with markup = cost × (1 + markup rate)
• Selling price for a target gross margin = cost ÷ (1 − margin rate)

If a part costs $2.00, a 20% markup produces a $2.40 selling price. A 20% gross margin requires a $2.50 selling price because $0.50 is 20% of the $2.50 selling price.

How to Calculate Projection Welding Cost Step by Step

Use the same sequence for every job. A repeatable method makes quotes easier to compare, review, and update.

1. Define the selling unit. Decide whether the customer will be charged per weld, good part, assembly, batch, or separate setup.
2. Set volume and yield assumptions. Record batch size, annual volume, started parts, destructive samples, expected rejects, and accepted parts.
3. Price material and purchased components. Include blanks, stampings, nuts, bolts, inserts, coatings, cleaning, packaging, and supplier minimums.
4. Estimate setup and non-recurring work. Include fixture design, programming, trials, qualification, gauges, setup labor, and first-article inspection.
5. Measure production labor. Break the cycle into loading, alignment, welding, unloading, checking, electrode care, handling, and packaging.
6. Apply loaded labor and machine rates. Use documented shop rates and make sure the same burden is not included twice.
7. Add energy and consumables. Use measured kWh, electrode-life records, cooling demand, cleaning supplies, and job-specific disposable items.
8. Add quality loss and overhead. Include inspection, test samples, expected rework, scrap, downtime, supervision, administration, and facility costs under a consistent accounting method.
9. Calculate price and test the assumptions. Apply markup or margin, then run sensitivity checks for labor, material, cycle time, yield, and batch size.

What Costs Belong in a Projection Welding Quote?

Separate costs into clear groups before calculating a unit price. This shows what drives the quote and helps prevent double counting.

Direct Production Costs

• Base material, stamped parts, fasteners, inserts, and coatings
• Operator and direct inspection labor
• Electrode wear, dressing media, cleaning supplies, and test pieces
• Machine time, measured energy, cooling, and compressed air
• Expected scrap and direct rework
• Job-specific packaging and labels

Setup and Non-Recurring Costs

• Fixture and gauge design
• Dedicated tooling, electrodes, and nests
• Machine programming and weld-schedule development
• Qualification samples and destructive testing
• First-article inspection and customer documentation
• Production setup and changeover labor

Charge non-recurring work separately when practical. If it must be included in the part price, divide it by a realistic committed volume rather than an uncertain lifetime forecast.

Indirect and Overhead Costs

• Supervision, planning, purchasing, and administration
• Rent, insurance, general utilities, and information systems
• Preventive maintenance and calibration support
• Reusable safety equipment and general shop supplies
• Quality-system, training, and recordkeeping costs

Use the overhead method approved by your accounting system. Do not add a broad overhead percentage if the same rent, maintenance, supervision, or depreciation is already included in the labor or machine rate.

How Do You Calculate Material and Electrode Cost?

Material cost should reflect what the shop actually buys and consumes, not only the finished part weight.

If your quote is based on deposited weld-metal weight rather than a projection-welded assembly, compare the separate welding cost per kg guide. Projection welding usually needs a part-and-yield model instead of a filler-deposition model.

For purchased parts, use:

Purchased material cost per started part = supplier unit price + inbound freight allocation + required outside processing

For sheet or coil processed in-house, use:

Material cost = gross purchased material cost ÷ usable parts produced from that material

This approach captures nesting loss, trim, remnants, minimum order quantities, and setup scrap. Add the cost of weld nuts, bolts, inserts, washers, plating, coating removal, cleaning, rust prevention, and special handling where required.

Convert electrode and supply use into a unit cost:

Electrode cost per weld = electrode-set cost ÷ verified welds per set

If a part receives four projection welds, multiply the electrode cost per weld by four. Include the labor and downtime for dressing or replacing electrodes separately unless the machine rate already covers that work.

Consumables may include:

• Electrode caps, inserts, or dies
• Dressing cutters, abrasive paper, and cleaning material
• Qualification coupons and destructive-test parts
• Job-specific disposable gloves, wipes, labels, and packaging
• Cooling-water treatment or filters when usage is measurable

How Do You Calculate Projection Welding Labor Cost?

Weld time may be only a small part of the labor cycle. Measure the full work sequence instead of estimating one blended number.

• Job setup and fixture change
• Material staging and replenishment
• Part loading and orientation
• Clamp or ram movement and squeeze time
• Weld pulse and hold time
• Part unloading and cooling
• Visual or dimensional inspection
• Electrode dressing and replacement
• Rework, labeling, packing, and movement to the next operation

Calculate direct labor per accepted part with:

Labor cost per good part = total expected direct labor-hours × loaded labor rate ÷ expected accepted parts

A loaded labor rate may include hourly wages, payroll taxes, benefits, paid time, and other labor burden under the shop’s accounting policy. Supervision and facility overhead should be included only if the shop normally builds them into that rate.

Setup Labor

Keep setup separate from production labor:

Setup labor per good part = setup hours × loaded setup rate ÷ expected accepted parts

Small batches usually cost more per part because the same setup time is divided across fewer accepted parts. A separate setup charge is often clearer than hiding all setup cost in the unit price.

Using the worked example below, 1.5 setup hours at $60 per hour creates $90 of setup labor. Spread across 970 accepted parts, that is about $0.093 per good part; spread across 485 accepted parts, it doubles to about $0.186 per good part. This is why batch size can change the unit price even when the weld cycle itself does not change.

Cycle Time and Operator Attendance

Do not assume that machine cycle time equals operator labor time. One operator may attend one machine continuously, tend several automated machines, or perform inspection while the machine cycles.

Use a time study or machine log for repeat work. For a new job, run representative trials that include normal loading, electrode care, checks, and short interruptions. Avoid using only the fastest observed cycle.

How Do You Calculate Machine and Power Cost?

Machine cost includes ownership and the support needed to keep the welding cell available. Power is only one part of that rate.

Machine-Hour Rate

A practical machine-hour rate can be calculated as:

Machine-hour rate = annual machine ownership and support cost ÷ practical productive machine-hours

The annual cost may include:

• Depreciation or lease cost
• Planned maintenance and expected repairs
• Calibration and safety inspection
• General tooling and fixture wear
• Cooling equipment and machine-specific services
• Allocated floor space, insurance, and support labor when not included elsewhere

Practical productive hours should account for scheduled shifts, holidays, planned maintenance, normal changeovers, and expected utilization. Dividing by every calendar hour will understate the machine rate.

Machine Depreciation Rate

A simple straight-line method is:

Annual depreciation = (purchase price − expected salvage value) ÷ useful life

Then divide annual depreciation by practical productive hours. Keep depreciation separate from maintenance unless the approved machine rate intentionally combines them.

• Use the same accounting method across similar quotes.
• Update productive-hour estimates when utilization changes.
• Keep customer-specific fixtures separate from the base machine.
• Do not recover the same machine cost through both overhead and the machine-hour rate.

Power Consumption Costs

The best energy estimate comes from a meter that measures the welding cell’s actual input kWh over a representative run. Include the welder, controller, cooling system, feeder, air compressor allocation, and other dedicated auxiliary equipment when material.

Use:

Energy cost per good part = measured batch kWh × utility energy rate ÷ expected accepted parts

If measured data is unavailable, use an input-side estimate rather than the low-voltage weld-secondary values.

• Single-phase real power: kW = volts × amps × power factor ÷ 1,000
• Balanced three-phase real power: kW = 1.732 × line-to-line volts × amps × power factor ÷ 1,000
• Energy: kWh = average kW × operating hours
• Energy cost: kWh × utility energy rate

Schneider Electric’s PM2200 documentation expresses balanced three-phase real power as 3 × line-to-neutral voltage × current × power factor. That is equivalent to the 1.732 × line-to-line-voltage form for a balanced system. Use the voltage basis that matches the meter, wiring configuration, and manufacturer documentation.

These equations are only estimates when current changes rapidly or the machine has a low duty cycle. A resistance welder may be rated in kVA, and short high-current pulses do not mean it draws nameplate current continuously.

Refer to the machine manual for the correct input basis. Use qualified electrical personnel for measurements inside or around energized equipment.

Some industrial utility bills include demand, time-of-use, delivery, or power-factor charges. Allocate these only when they are material and your accounting policy provides a reasonable method. Do not add the full facility demand charge to one job.

Ancillary Equipment Expenses

Ancillary equipment may include cooling systems, fixtures, guards, cables, transformers, controls, feeders, sensors, weld monitors, gauges, extraction, and electrode-dressing tools.

Classify each item as:

• Dedicated tooling: Charged to one customer or one part family
• Reusable capital equipment: Recovered through a machine or overhead rate
• Operating expense: Charged according to measured or expected use
• Replacement item: Spread over its verified service life

For customer-specific tooling, either charge it separately or divide its unrecovered cost by the committed volume. State who owns, stores, maintains, repairs, and replaces the tooling.

How Do Scrap, Rework, and Yield Affect Cost?

Quality costs should be tied to the actual acceptance plan. Visual inspection alone cannot prove the internal quality of every projection weld. A 2024 Welding in the World study on resistance projection welds notes that the weld itself is not visible from outside and that destructive testing remains a common quality-assurance method because established NDT options are limited for projection welds.

Depending on the part and customer requirement, validation may include pull, push-off, peel, shear, torque, dimensional, cross-section, metallographic, or corrosion testing.

Process monitoring may record current, voltage, force, and projection collapse. A monitor does not prove weld quality by itself; its limits should be correlated with tested acceptable and unacceptable parts.

Add the cost of:

• Startup and weld-schedule samples
• First-article inspection
• Destructive samples removed from sellable output
• Routine gauges and inspection labor
• Weld-monitor data collection and review
• Expected rework labor and additional machine time
• Scrapped material and purchased components
• Containment, sorting, and documentation risk when justified by history

Calculate final yield with:

Final yield = accepted parts ÷ started parts

Then calculate unit cost using accepted parts. Do not add a large scrap percentage and also divide by a reduced good-part quantity unless the spreadsheet is intentionally designed to treat different losses separately.

How Do You Add Overhead, Waste, and Profit?

Overhead converts direct manufacturing cost into the full cost of running the business. Apply it through one consistent method.

Common methods include:

• A percentage of direct labor cost
• A burdened labor rate
• A machine-hour rate
• An activity-based rate for purchasing, engineering, inspection, or setup
• A blended shop rate

Your overhead may include rent, general utilities, insurance, supervision, administration, training, quality systems, information technology, and facility maintenance. The exact method should match your accounting records.

Markup, Margin, and Commercial Risk

Apply the selected pricing method after calculating full expected cost. The rate may reflect order size, capacity, payment terms, warranty exposure, material volatility, schedule risk, and the length of the price commitment.

Keep these commercial items visible rather than hiding them in a vague contingency:

• Minimum order or minimum batch charge
• Separate setup or changeover charge
• Tooling and engineering charge
• Expediting or overtime charge
• Special packaging and freight
• Taxes or duties where applicable
• Material-price adjustment terms
• Quote expiration date and volume assumptions

Worked Example: Projection Welding Cost Per Part

This sample shows the structure of a projection welding quote. Replace every number with actual shop data before pricing live work.

Sample Assumptions

• 1,000 parts started
• 970 accepted parts expected after samples, scrap, and rework
• 97% final yield
• Four projections per part
• 1.5 setup labor-hours
• $60 loaded labor rate
• 0.015 production labor-hour per good part
• All listed costs are calculated per accepted part

A 20% markup on $2.10 produces:

$2.10 × 1.20 = $2.52 selling price per part

A 20% gross margin produces:

$2.10 ÷ 0.80 = $2.625, rounded to $2.63 per part

Freight, tax, dedicated tooling, special packaging, and expediting are not included in this sample. Add or list them separately when applicable.

Sample Sensitivity Check

The sensitivity check shows which inputs need firm evidence. A small labor change has a larger effect than the same percentage change in a low-cost material item.

How Do You Validate a Projection Welding Quote?

Review the complete quote with production, quality, purchasing, and accounting when the job carries meaningful volume or risk.

• Is the current drawing revision identified?
• Are welds per part and parts per cycle correct?
• Are started parts, destructive samples, yield, and accepted parts stated?
• Does setup include fixture installation, schedule verification, and first-piece approval?
• Are labor and machine hours based on realistic cycles rather than the fastest trial?
• Are electrode dressing, changes, cooling, and maintenance included?
• Does the inspection plan match the customer requirement?
• Are dedicated tooling and qualification costs charged or amortized clearly?
• Has overhead been counted once and only once?
• Is the price based on the intended markup or gross margin?
• Are minimum quantity, payment terms, freight, packaging, and quote validity stated?
• Has the team tested higher material prices, lower yield, and slower cycle time?

After the first production batch, compare estimated and actual values. Update the routing, electrode-life assumption, yield, cycle time, and machine rate before quoting the next release.

Common Mistakes That Distort Projection Welding Costs

Projection welding quotes often fail because the model ignores small but repeatable losses.

• Dividing total cost by started parts instead of accepted parts
• Leaving setup, qualification, or first-article time out of the quote
• Using peak nameplate current as continuous electrical demand
• Omitting power factor, phase configuration, or auxiliary equipment
• Forgetting electrode dressing, replacement labor, and downtime
• Ignoring destructive samples, startup scrap, and containment risk
• Using an unrealistic number of annual productive machine-hours
• Counting rent, maintenance, or supervision in two different rates
• Calling a markup percentage a profit margin
• Using old supplier prices for repeat work
• Spreading tooling over forecast volume that the customer has not committed to buy
• Failing to state minimum quantity, setup charge, or quote expiration

A short review of these items can protect the margin and make the final price easier to explain.

Frequently Asked Questions

How do projection welds affect product fatigue life long-term?

Fatigue life cannot be predicted from the process name alone. It depends on joint geometry, load direction, material, projection collapse, weld size, defects, stiffness changes, and the service environment. Validate fatigue-critical joints with the applicable design standard, customer requirements, and representative testing.

Can projection welding be automated for small batch runs?

Yes. Small batches can use automated or semi-automated loading, force control, weld monitoring, and data collection. The savings must exceed the programming, fixture, changeover, validation, and maintenance costs. Quick-change tooling and repeat part families improve the business case.

How do environmental rules affect welding consumable disposal?

Do not assume that every used electrode or shop material is hazardous, or that it is automatically ordinary scrap. Identify the material and contamination, review the process that created the waste, and use testing when existing knowledge is not enough. The U.S. EPA hazardous-waste guidance states that generators must determine whether their waste is hazardous; state and local requirements may add obligations. Follow the rules that apply to storage, labeling, transport, recycling, and disposal.

What quality inspection methods are best for projection welds?

There is no single best method for every part. Visual and dimensional checks may be combined with pull, push-off, peel, shear, torque, cross-section, metallographic, or other tests. Current, voltage, force, and displacement monitoring can support process control after the readings have been correlated with verified weld quality.

How do joint geometry variations change welding parameters?

Geometry can change contact area, current path, heat balance, force distribution, projection collapse, and fixture access. Do not adjust current or time from thickness alone. Develop and validate the complete schedule for the actual material, coating, projection, electrode, force, and machine.

How should you price small projection welding batches?

Small batches usually need a higher unit price because setup, qualification, tooling, inspection, and material handling are divided across fewer good parts. A separate setup charge and minimum batch charge often make the quote clearer and protect repeat-order pricing.

What input changes affect projection welding cost the most?

The largest drivers are often direct labor time, batch size, final yield, material and fastener price, machine utilization, inspection requirements, and tooling cost. The largest driver varies by job, so run a sensitivity check instead of relying on one general ranking.

What is the difference between markup and gross margin?

Markup is calculated as a percentage of cost. Gross margin is calculated as a percentage of selling price. For a 20% markup, multiply cost by 1.20. For a 20% gross margin, divide cost by 0.80.

How should power cost be measured for a projection welder?

Measure the welding cell’s input kWh over a representative batch whenever possible. A nameplate-only estimate can be misleading because resistance welders use short high-current pulses and may be rated in kVA. Include relevant cooling and auxiliary loads, then divide the batch energy cost by accepted parts.

Sources

1. AMADA Weld Tech — Fundamentals of Small Parts Resistance Welding — projection welding principles, weld schedules, testing, and process monitoring
2. American Welding Society — C1 Committee on Resistance Welding — current AWS resistance-welding publications and committee scope
3. OSHA 29 CFR 1910.255 — Resistance Welding — operator training, guarding, shields, controls, grounding, and inspection
4. Schneider Electric — Total Power Calculation — single-phase and three-phase real-power calculations using power factor
5. U.S. Environmental Protection Agency — Hazardous Waste Basics — generator responsibility for waste identification, management, and documentation
6. Welding in the World — Non-destructive characterization of resistance projection welded joints — projection-weld inspection limits and quality-assurance context

Conclusion

A dependable projection welding quote converts every batch input into a cost per accepted part. Start with materials, setup, production labor, machine time, energy, electrodes, tooling, inspection, rework, and overhead. Divide the full expected batch cost by good output, then apply either a clearly labeled markup or gross-margin formula. Record actual results after production so each future quote becomes faster, more accurate, and easier to defend.