Welding Business: Entity Structure, S-Corp Election, and Tax Planning

By Yarik Yarosh, CPA ·September 5, 2026 ·Updated October 4, 2026 ·5 min read

Written by Yarik Yarosh, CPA (US & Canada) September 5, 2026 · FL CPA license AC61704 · CPA Ontario

Welding and metal fabrication is classified under NAICS 332710 (Machine Shops) or 332312 (Fabricated Structural Metal Manufacturing) and isn’t a Specified Service Trade or Business (SSTB) under IRC 199A. The full 20% QBI deduction applies at any income level. Welding businesses come in two main forms: mobile welding (the welder goes to job sites with a truck-mounted rig) and shop-based fabrication (customers bring work to the shop or the shop builds custom products). The entity structure decision depends on which model the business follows, because shop-based fabrication has higher fixed costs (lease, utilities, shop equipment) that reduce net profit relative to mobile welding.

✓Key takeaway

Welding business tax profile:

SSTB status: NOT an SSTB. Welding is a skilled trade, not a professional service. Custom fabrication, structural welding, pipe welding, and repair welding are all trade activities.

Two business models:

Model	Startup Cost	Margins	Revenue Ceiling
Mobile welding	$15,000-$40,000 (truck + portable welder)	50-70% (lower materials)	$150,000-$250,000 (limited by one person)
Shop fabrication	$50,000-$200,000 (lease + equipment)	25-45% (higher materials, overhead)	$500,000+ (scalable with employees)

Mobile welding equipment:

Equipment	Cost Range
Welding truck (F-350/F-450, used)	$25,000-$50,000
Engine-driven welder (Lincoln, Miller)	$3,000-$12,000
Plasma cutter	$1,500-$5,000
Grinding/cutting tools	$500-$2,000
Safety equipment (helmet, leathers, ventilation)	$500-$1,500
Consumables startup (rod, wire, gas)	$500-$1,000
Total mobile startup	$31,000-$71,500

Shop fabrication equipment (additional):

Equipment	Cost Range
MIG welder (industrial)	$3,000-$10,000
TIG welder	$2,000-$8,000
Bandsaw (metal cutting)	$2,000-$8,000
Drill press	$1,000-$5,000
Bending/forming equipment	$3,000-$15,000
Overhead crane/hoist	$2,000-$10,000
Welding tables	$1,000-$5,000
Air compressor (industrial)	$2,000-$5,000
Total shop addition	$16,000-$66,000

S-Corp break-even (mobile welding):

Net Profit	Sole Prop SE Tax	S-Corp FICA (on $50K salary)	FICA Savings	Admin Cost	Net Savings
$50,000	$7,065	$7,650	($585)	$2,000	($2,585) loss
$70,000	$9,891	$7,650	$2,241	$2,000	$241
$90,000	$12,717	$7,650	$5,067	$2,000	$3,067
$120,000	$16,956	$7,650	$9,306	$2,000	$7,306

S-Corp break-even for mobile welding: $60,000-$70,000 net profit.

Material costs (significant variable):

Material	Typical Cost	% of Revenue (fabrication)
Mild steel (hot rolled)	$0.40-$0.80/lb	15-25%
Stainless steel	$1.50-$3.00/lb	20-35%
Aluminum	$1.00-$2.50/lb	15-25%
Welding wire/rod	$2-$8/lb	2-5%
Shielding gas (argon, CO2)	$30-$60/tank	1-3%

Material costs for fabrication shops are 15-30% of revenue. Mobile welding (mostly repair work) uses fewer materials, often under 10% of revenue.

Certification ROI:

Certification	Cost	Revenue Impact
AWS D1.1 (Structural)	$500-$1,000	Opens structural/commercial jobs (+$15-$30/hour)
API 1104 (Pipeline)	$500-$1,000	Pipeline work ($40-$80+/hour, travel)
ASME Section IX (Pressure vessels)	$500-$1,000	Refinery/industrial work ($35-$60/hour)
CWI (Certified Welding Inspector)	$1,500-$3,000	Inspection services ($50-$80/hour, desk + field)

Certifications pay for themselves in 1-3 months. Pipeline-certified welders earn 2-3x general welding rates.

How should a welder choose their entity structure?

Hypothetical example

Round numbers. A mobile welder. Year 3. Single filer. Net profit: $85,000. AWS D1.1 certified. Serves construction companies, farmers/ranchers, and homeowners.

Current setup: sole proprietorship with LLC

Current tax:

SE tax: $85,000 x 92.35% x 15.3% = $12,003
Income tax: approximately $10,200
QBI deduction: $85,000 x 20% = $17,000 (saves $3,740)
Total after QBI: $18,463

With S-Corp election: Reasonable salary: $50,000 (mobile welder, certified, 3 years experience, rural area) Distributions: $35,000

S-Corp tax:

FICA on salary: $50,000 x 15.3% = $7,650
Income tax: approximately $10,200 (same total income)
QBI deduction: still $85,000 x 20% = $17,000 (salary counts as W-2 wages for QBI limit, but below threshold so limit doesn’t apply)
S-Corp admin: $2,000
Total: $15,850

Annual savings: $2,613

Year 1 equipment scenario: The welder buys a used F-350 welding truck ($35,000, over 6,000 lbs GVWR) and a Lincoln Ranger 330MPX ($6,000).

Section 179: $41,000 Year 1 net profit before equipment: $85,000 After Section 179: $44,000

As sole proprietor (Year 1, before S-Corp makes sense at $44K net):

SE tax: $44,000 x 92.35% x 15.3% = $6,214
Income tax: minimal
Total Year 1 tax: approximately $7,000

Year 2 (full profit returns, elect S-Corp): $15,850

Material deduction tracking: The welder buys welding rod, wire, and gas throughout the year. Annual consumables: $4,500.

These are deducted as supplies (direct materials used on jobs). No inventory tracking needed for consumables used on jobs (not held for resale). The welder can deduct $4,500 on Schedule C (or as an S-Corp expense) in the year purchased.

For fabrication jobs with customer-supplied materials: only the labor portion is revenue. The material the customer provides isn’t the welder’s income or expense.

For fabrication jobs where the welder buys materials: the material cost is deducted as cost of goods sold or as a materials expense. If the welder maintains an inventory of steel and aluminum, the uniform capitalization rules (UNICAP) may apply for businesses with average annual gross receipts over $32 million (for 2026; irrelevant for small welding shops).

Shop lease considerations: If the welder transitions to a shop:

Lease: $1,500-$3,000/month ($18,000-$36,000/year)
Utilities (three-phase power for welding): $400-$800/month
Insurance (shop policy): $2,000-$4,000/year

These fixed costs reduce net profit by $25,000-$50,000. A shop welder needs $150,000+ in gross revenue before the shop model outperforms mobile welding on net profit. Many welders operate both models: a small shop for fabrication jobs and a mobile rig for field repair work.

Illustrative numbers only, not a real client and not advice for your facts.

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Cite this page

Yarik Yarosh, CPA. "Welding Business: Entity Structure, S-Corp Election, and Tax Planning." Blue Cloud CPA, September 5, 2026, updated October 4, 2026. https://bluecloudcpa.com/guides/welding-fabrication-entity-structure-scorp

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.

Welding Business: Entity Structure, S-Corp Election, and Tax Planning

How should a welder choose their entity structure?

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