Shelle Parsons What is Young’s Modulus (Modulus of Elasticity)? Young’s Modulus (or modulus of elasticity) is a measure of a material’s stiffness. It tells you how much a material will deform elastically under a given load. A high Young’s Modulus means a stiff material (like steel); a low value means a flexible material (like rubber). Formula: E … Read more
Standard Key & Keyway Dimensions Square and rectangular keys transmit torque between shafts and hubs (gears, pulleys, couplings). The key size is determined by the shaft diameter — there’s a standard match. Square & Rectangular Key Sizes (ANSI B17.1) Shaft Diameter (in) Key Width (in) Key Height (in) Key Type 5/16 to 7/16 3/32 3/32 … Read more
Standard Dowel Pin Dimensions Dowel pins locate and align parts in assemblies. Unlike bolts (which have clearance), dowel pins are precision ground to tight tolerances and pressed into reamed holes. They’re the backbone of fixture design, mold tooling, and any assembly that needs to come apart and go back together in exactly the same position. … Read more
Set Screw Holding Power & Tightening Torque Set screws hold collars, pulleys, gears, and knobs on shafts. Their holding power depends on the point style, material hardness, and seating torque. Under-torqued set screws are the most common cause of components slipping on shafts. Recommended Tightening Torque Set Screw Size Cup Point Torque (in-lbs) Axial Holding … Read more
Interference Fits for Bearings, Pins & Bushings A press fit (interference fit) is when the shaft is slightly larger than the hole, requiring force to assemble. The interference creates a clamping force between the parts — no fasteners needed. Getting the interference right is critical: too little and the part slips, too much and you … Read more
Reading Weld Symbols Weld symbols on engineering drawings tell the welder exactly what joint to make, where to put it, and how big it should be — without writing paragraphs of notes. The system is defined by AWS A2.4 and it’s more logical than it looks once you understand the structure. The Weld Symbol Structure … Read more
Bolt Clearance Hole Sizes When a bolt passes through a part without threading into it, the hole needs to be slightly larger than the bolt diameter. How much larger depends on how precisely the holes need to align. US Bolt Clearance Holes Bolt Size Close Fit (in) Normal Fit (in) Loose Fit (in) #4 (0.112) … Read more
How It Works Structural beam analysis determines internal forces, bending moments, and deflections that develop when loads are applied to horizontal structural members. These calculations form the foundation of safe structural design by ensuring beams can support applied loads without failure or excessive deflection. Shear Force (V) represents the internal force tending to cut through … Read more
What is Tolerance Stack-Up? When multiple parts assemble together, each dimension has a tolerance. Those tolerances accumulate. Tolerance stack-up analysis tells you whether your assembly will work — or whether you’ll be forcing parts together on the shop floor. There are two fundamental approaches: Worst Case (everything goes wrong simultaneously) and RSS/Statistical (realistic probability-based analysis). … Read more
Choosing the Right Stainless Steel There are over 150 grades of stainless steel. In practice, you’ll use about five of them 90% of the time. This guide covers those five — when to use each, what to watch out for, and the trade-offs between them. The Big Five — Quick Comparison Property 304 316 303 … Read more