Welding Calculators & Fabrication Tools
Good welds start before you strike an arc. You need the right machine settings, the right gas, the right filler and, on thick or hard steel, the right preheat. This hub brings the welding and fabrication calculators on Machinist Central together in one place.
The setup tools help you dial in the machine. Find a starting wire feed speed and amperage for MIG, pick a tungsten type and size for TIG, estimate shielding gas use and check whether a job will push your welder past its duty cycle.
The engineering tools are for when the steel or the code matters. The carbon equivalent calculator shows how prone a steel is to cracking. The preheat tool suggests a starting preheat temperature. The heat input calculator works out heat input from volts, amps and travel speed, which many weld procedures limit. The shrinkage tool estimates how much a joint will pull and distort.
For quoting, estimate weld metal volume, wire use, deposition rate and arc-on time, so you can price a job on real numbers.
The fabrication tools cover the work around the welding: printable tube notch templates, tube bending layout for roll cages and frames, miter and compound saw angles, and a cut list optimizer that fits parts into stock lengths with less waste.
These calculators give good starting values. They do not replace a qualified weld procedure, the filler maker's data or the code your work has to meet. Test on scrap first.
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Calculators
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Welder setup
MIG WFS & Amps
Estimate amperage based on wire feed speed and diameter for MIG/Flux-Core.
Open Calculator: MIG WFS & AmpsTIG Tungsten Guide
Selection and grinding guide for TIG electrodes based on amperage and material.
Open Calculator: TIG Tungsten GuideShielding Gas Calc
Estimate gas consumption and cost per batch including pre/post flow losses.
Open Calculator: Shielding Gas CalcDuty Cycle Estimator
Calculate safe arc-on time limits when operating at high amperages.
Open Calculator: Duty Cycle EstimatorWeld engineering and quality
Carbon Equivalent (CE)
Analyze steel weldability and cracking risk based on chemical composition.
Open Calculator: Carbon Equivalent (CE)Weld Pre-heat Calc
Determine recommended pre-heat temperatures to prevent Cold Cracking in steel.
Open Calculator: Weld Pre-heat CalcWeld Heat Input
Calculate net energy transfer (kJ) based on voltage, amps, and travel speed.
Open Calculator: Weld Heat InputWeld Shrinkage
Predict transverse and longitudinal shrinkage caused by thermal distortion during welding.
Open Calculator: Weld ShrinkageFillet Weld Gauge
Check leg size and throat thickness against structural drawing requirements.
Open Calculator: Fillet Weld GaugeWeld cost and time
Weld Volume Estimator
Estimate weld volume and required consumable weight (wire/rods) for fillets and v-grooves.
Open Calculator: Weld Volume EstimatorDeposition Rate
Calculate the weight of filler metal deposited per hour factoring in process efficiency.
Open Calculator: Deposition RateArc-On Time Tool
Analyze welder productivity and operating factor based on time or wire use.
Open Calculator: Arc-On Time ToolFabrication layout and cutting
Tube Notcher Template
Generate 1:1 printable paper wrap templates for tube saddle (fish-mouth) joints.
Open Calculator: Tube Notcher TemplateTube Bending Layout
Calculate cut lengths and start-of-bend marks for chassis tubing and roll cages.
Open Calculator: Tube Bending LayoutMiter & Compound Angle
Calculate miter and bevel angles for cutting compound joints on a saw.
Open Calculator: Miter & Compound AngleLinear Cut List Optimizer
Optimize cutting 1D stock bars (tubing/extrusions) to minimize waste and kerf loss.
Open Calculator: Linear Cut List OptimizerBandsaw Optimizer
Optimize bandsaw speeds and tooth pitch based on material thickness and type.
Open Calculator: Bandsaw OptimizerGuides
How to Make DXF Files for Laser & Plasma Cutting
Make clean DXF files for laser, plasma, waterjet and CNC router cutting, with worked examples using three free tools.
Reference charts
Frequently asked questions
- How do I calculate weld heat input?
- Heat input in kJ per inch = (volts × amps × 60) ÷ (travel speed in inches per minute × 1000). Some codes also apply a thermal efficiency factor for the process. The Weld Heat Input calculator does the math for you.
- When do I need to preheat steel before welding?
- Preheat is needed when the steel is thick, has a high carbon equivalent or the joint is highly restrained. It slows cooling and lowers the risk of hydrogen cracking. Use the Carbon Equivalent and Weld Pre-heat calculators for a starting temperature, then check your welding code.
- What is welder duty cycle?
- Duty cycle is the percentage of a 10-minute period that a welder can run at a given amperage without overheating. A 30% duty cycle at 200 A means 3 minutes of welding, then 7 minutes of rest.
- Which tungsten should I use for TIG welding?
- 2% lanthanated tungsten is a good all-round choice for both AC and DC. Thoriated tungsten is common for DC work on steel, and pure tungsten is the older choice for AC aluminum. The TIG Tungsten Guide helps you pick the type and size.