What are the sizes and dimensions of commonly available material stock you can work with as a design starting point as a mechanical design engineer?
Pipe material stock sizes?
Tubing sizes?
Material variations?
Grades of Steel?
Chemistry of steel?
Grades of castings?
Mechanical properties of various grades of material?
Drill sizes?
Tap size?
How machinable are different grades of material? Can you easily produce the design?
Find out some of the materials and tools you can use by exploring material grade, chemistry, mechanical properties and corrosion resistance. These are a useful guideline, but always remember to do your own research as well.
Common Structural Steel Shapes Structural steel comes in standardized shapes that are designed for efficient load-carrying. Here are the dimensions and properties for the shapes you’ll encounter most in machine design, fabrication, and construction. Steel Angle (L-shapes) Size (legs × thickness) Weight (lb/ft) Area (in²) Ix (in⁴) Iy (in⁴) L1×1×1/8 0.80 0.234 0.022 0.022 L1-1/2×1-1/2×1/8 … Read more
Choosing the Right Engineering Plastic Engineering plastics bridge the gap between commodity plastics (like polyethylene) and metals. They offer strength, wear resistance, chemical resistance, and dimensional stability that commodity plastics can’t match — at a fraction of the weight and cost of metals. Properties Comparison Table Property Nylon 6/6 Delrin (POM) PEEK Polycarbonate UHMW-PE Acetal … Read more
What is Coefficient of Thermal Expansion (CTE)? The Coefficient of Thermal Expansion (CTE) tells you how much a material will expand or contract when its temperature changes. This is critical for assemblies where dissimilar materials are joined, or for parts that experience wide temperature swings. Formula: ΔL = α × L₀ × ΔT ΔL = … Read more
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
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
Common Aluminum Alloys for Engineering Not all aluminum is the same. The alloy designation tells you everything about its strength, machinability, weldability, and corrosion resistance. Here’s the practical comparison for the alloys you’ll actually encounter. Properties Comparison Table Property 6061-T6 7075-T6 2024-T3 5052-H32 Tensile Strength (ksi) 45 83 70 33 Yield Strength (ksi) 40 73 … Read more
Why Hardness Matters Hardness testing is the quickest way to verify a material’s heat treatment and estimate its tensile strength without destroying the part. In practice, you’ll encounter three scales constantly: Brinell (HB), Rockwell B (HRB), and Rockwell C (HRC). Conversion Table — Steel These conversions are approximate and apply to carbon and alloy steels. … Read more
The Complete Drill Size Reference Why does this chart exist? Because someone at some point decided that drill bits should come in four completely different naming systems — fractional inches, letter sizes (A–Z), number/gauge sizes (#1–#97), and metric. And engineers need to convert between all of them constantly. This master chart lists all standard drill … Read more
What is NPT? NPT (National Pipe Thread) is the US standard for tapered pipe threads. The taper is 1°47′ (3/4 inch per foot), which means the threads wedge tighter as you screw them together — creating a seal. NPT threads require thread sealant (Teflon tape or pipe dope) for a leak-free connection. NPT vs. NPTF: … Read more
What is Machinability? Machinability is how easy (or difficult) a metal is to cut with standard machining operations — turning, milling, drilling. It’s expressed as a percentage relative to AISI 1212 steel, which is the baseline at 100%. Higher percentage = easier to machine = lower cost. If you’re selecting a material and you have … Read more