Tensile Testing Machine Demonstration Model

Every mechanical engineer meets the stress–strain curve in the second year — and most meet it only as a diagram, because universal testing machines are expensive, shared, and often booked out. This project brings the experiment to the student's own bench as a demonstration-scale model. A welded mild-steel frame carries a hand-crank screw drive: turning the crank draws the moving grip away from the fixed grip, stretching a dog-bone specimen held in wedge grips. A dial force gauge (0–500 kgf) in the load path reads the tensile force, and a ruler scale beside the specimen tracks elongation. The student loads the specimen in steps, records force and elongation, converts to stress and strain, and plots the curve — finding yield and ultimate strength from their own data. The report is explicit that this is a demonstration model: hand-cranked, analog-read, and honest about its limits versus a calibrated UTM.

1. The dog-bone specimen is clamped between the fixed and moving wedge grips in the steel frame.
2. The student zeros the dial force gauge and notes the initial gauge length on the ruler scale.
3. Turning the hand crank advances the screw, pulling the moving grip and stretching the specimen in small steps.
4. At each step the student records the force from the dial gauge and the elongation from the ruler.
5. Force and elongation are converted to engineering stress and strain using the specimen's measured cross-section.
6. The plotted curve reveals the elastic region, yield point, ultimate strength and fracture — from the student's own readings.

Tech stack:

• Welded mild-steel frame
• Lead-screw + hand crank drive
• Wedge grips
• 0–500 kgf dial force gauge
• Ruler elongation scale
• Machined dog-bone specimens
• Manual test procedure + calculation sheets

• [Welded steel frame] A rigid mild-steel box frame, welded and bolted, carries the tensile load without flexing — the fabrication itself is part of the project.
• [Hand-crank screw drive] A lead-screw with a crank handle applies the tensile load smoothly and controllably, with the mechanical advantage documented in the report.
• [Wedge grips] Self-tightening wedge grips hold the dog-bone specimen — the harder the pull, the tighter they bite, just like full-size machines.
• [Dial force gauge] A 0–500 kgf analog force gauge in the load path gives a direct, readable load at every step — no electronics to hide behind.
• [Elongation scale] A fixed ruler scale beside the specimen lets the student read extension to the millimeter for the strain calculation.
• [Dog-bone specimens] The kit includes machined flat dog-bone specimens, with the specimen drawing and dimensions documented.
• [Stress–strain procedure] A complete test procedure — stepwise loading, force/elongation logging, stress–strain computation and curve plotting — with recording sheets.

• Working tensile testing machine demonstration model
• Set of machined dog-bone specimens
• Fabrication drawings (frame, grips, screw drive)
• Step-by-step tensile test procedure with recording sheets
• Stress–strain calculation templates
• Project report PDF (tensile theory, machine design, student test results)
• PPT presentation for final review
• Viva Q&A preparation document