Mechanical

Mechanical12 Aug 2026 · 10 min read

Copper-Base Spring Alloys

The three copper-base spring materials — spring brass, phosphor-bronze and beryllium-copper — with compositions, tensile strengths by temper and diameter, moduli, electrical con…

Mechanical12 Aug 2026 · 9 min read

Design Stresses and Fatigue

How to choose a safe working stress for a spring — fatigue theory, the three service classes and their cycle ranges, reading the recommended design-stress curves, the endurance …

Flat High-Carbon Spring Steel Strip

Cold-rolled spring strip to ASTM A682 — the two steels that cover 95 % of flat springs, rolled tempers No. 5 to No. 1, mill-hardened T1–T3 strip with strength by thickness, edge…

Mechanical12 Aug 2026 · 9 min read

High-Carbon Spring Steels

The workhorse cold-coiled spring wires — music wire A228, hard-drawn A227 and A679, oil-tempered A229 and valve-quality A230 — with sizes, tensile ranges, moduli by diameter, el…

Hot-Rolled Bars for Hot-Coiled Springs

Heavy springs are coiled red-hot from annealed bar. Carbon bars to ASTM A68/SAE 1095, the A331 alloy families 5160, 9260, 4150 and 8645–8660, tool steels for special cases, and …

Mechanical12 Aug 2026 · 10 min read

Metallurgy of Spring Steels

How spring steel is made — from ore, flux and coke through the blast furnace and basic-oxygen converter to killed ingots, billets, patented rod and cold-drawn wire — and what ea…

Nickel-Base Spring Alloys

Monel 400 and K-500, Inconel 600 and X-750, and the minor nickel spring alloys — compositions, tensile strengths by diameter, the fall of modulus with temperature, service-tempe…

Mechanical12 Aug 2026 · 10 min read

Stainless Steel Wire and Strip

Spring stainless in three families — cold-worked austenitic 302/304/316, hardenable martensitic 414/420/431 and precipitation-hardening 17-7 PH — with properties, compositions, …

Acme Screw Threads

The power-transmission thread: the trapezoidal Acme and Tr forms, the power-screw torque equations, a Tr30×6 jack worked in full — raising, lowering, efficiency and the self-loc…

Adhesives and Sealants

Joining without holes: how adhesives hold and why surfaces decide, the shear-good-peel-bad design law with a lap joint worked to 4.69 kN, the chemistry shelf from epoxy to silic…

Allowances and Tolerances for Fits

Limits and fits: why tolerances exist, the vocabulary of limits and deviations, clearance, transition and interference fits, the ISO grade system with the standard tolerance uni…

Arbors, Chucks and Spindles

Holding the work and the tool: three-jaw, four-jaw and collet chucks and their runout, arbors for milling cutters, the spindle that drives them, and why gripping force falls wit…

Ball and Acme Leadscrews

The screw as a machine axis: Acme in service and the recirculating ball screw side by side, the same five-kilonewton job priced on both bills — drive torque, holding duty, heat …

Ball, Roller and Needle Bearings

Rolling replaces sliding: the catalogue family from deep-groove to taper and needle, the L10 life equation worked in hours with its brutal cube law, the statistics of rolling fa…

Bevel Gears

Bevel gears for intersecting shafts: pitch cones and cone angles, straight versus spiral bevel, cone distance, the back-cone or Tredgold approximation and equivalent teeth, mitr…

British Fasteners

The British thread systems and their legacy: the Whitworth 55-degree form with its rounded crests, BSW and BSF, the metric-based British Association series, and British Standard…

Broaches and Broaching

Broaching a finished form in a single pass: the broach as a bar of progressively taller teeth, the rise per tooth that sets how much each removes, tooth pitch and cutting force,…

Buttress Threads

The one-way thread: the asymmetric 7°/45° form, the flank-angle arithmetic showing buttress cuts nut-bursting force 4.7 times below the 60° vee while matching square-thread effi…

Calculating Thread Dimensions

One dimension generates the whole thread: where the constants 0.6495, 1.0825, 1.2269 and 0.9382 come from in the 60° triangle, the working diameters of an M10×1.5 computed in fu…

Cams

Cams and followers: the displacement diagram, the four standard motion laws (uniform velocity, simple harmonic, parabolic and cycloidal) compared by peak acceleration and smooth…

Cap and Set Screws

Two fasteners with opposite jobs: the socket head cap screw that clamps at class 12.9 strength through a hex socket, and the headless set screw that locks a hub to a shaft by pr…

Cemented Carbides

Cemented carbide cutting-tool material: tungsten carbide grains in a cobalt binder, how cobalt content trades hardness against toughness, the ISO application groups, coatings, a…

CNC Numerical Control Programming

Programming computer numerical control machines: the coordinate systems and axes, G-codes and M-codes, setting spindle speed and feed from cutting data, linear and circular inte…

Couplings, Clutches and Brakes

One friction physics, three jobs: couplings that join shafts for good, clutches that join them at will, and brakes that turn motion into heat — with the clutch torque line worke…

Cutting Speeds and Feeds

Choosing the three cutting parameters — speed, feed and depth — and what each controls: tool life through speed, surface finish through feed and nose radius, and metal removal t…

Cutting Tools

The fundamentals of metal cutting: single-point tool geometry, rake and clearance angles and the tool signature, cutting speed and how it sets spindle speed, material removal ra…

Disc Springs

Belleville disc springs: cone geometry and the h/t ratio, the nonlinear force-deflection character with computed curves, series and parallel stacking arithmetic, friction and gu…

Drafting Practices

Engineering drawing essentials: the drawing as a contract, first- and third-angle projection, line conventions, views and sections, dimensioning rules with datum-versus-chain ac…

Electric Motors

The prime mover as a mechanical component: synchronous speed and slip, the induction motor's torque–speed curve with a 3 kW point worked, starting methods and the exact one-thir…

Electrical Discharge Machining

Machining by spark erosion: how EDM removes metal with no cutting force so it cuts any conductive material however hard, the spark gap and overcut, electrode wear, the finish-ve…

Elements, Heat, Mass and Weight

The physical starting points for materials work: density and how it turns a volume into a weight, specific heat and the energy to change temperature, thermal expansion, and wher…

Estimating Speeds and Machining Power

Working out the power, torque and time a cut demands: specific cutting energy and power from metal removal rate, motor power through efficiency, cutting torque, and machining ti…

Files and Burs

Hand and rotary shaping tools: single- and double-cut files and their coarseness grades, why a file is harder than the work, filing technique, and rotary burs with their high sp…

Finishing

Treating a component's surface after machining: electroplating and Faraday's law of deposition, anodising, galvanising and sacrificial protection, organic and powder coatings, a…

Flexible Belts and Sheaves

Grip is exponential: the capstan law worked flat and vee, the groove that multiplies friction three times over, a real drive priced in kilowatts, the timing belt that trades sli…

Fluid Mechanics

Fluid fundamentals for machines: properties and viscosity, pressure and head, Pascal's principle in hydraulics, buoyancy, continuity and Bernoulli, Reynolds number and flow regi…

Forming Tools

Form tools that cut a whole profile in one plunge: flat and circular form tools, why the profile must be corrected for rake, the heavy full-width cutting force they generate, an…

Gear Trains

Gear trains from simple to planetary: overall ratio of simple and compound trains, the role of idlers, the epicyclic train equation with a fixed-ring worked example, and where e…

Grinding and Other Abrasive Processes

The abrasive processes and their tools: the grinding-wheel marking system decoded, the abrasive types and when each is used, and the finer processes of honing, lapping and super…

Grinding Feeds and Speeds

The parameters of grinding: high wheel surface speed against slow work speed, wheel rpm from surface speed, the tiny depths of cut, the grinding ratio, and the burst-speed limit…

Hardening, Tempering and Annealing

The heat treatment of steel: the iron-carbon transformations behind it, quench hardening and the martensite it forms, tempering to restore toughness, annealing and normalising t…

Helical Coil Screw Thread Inserts

The wire coil that puts a steel thread into soft metal: why aluminium needs far more thread engagement than steel, how a helical coil insert works, fitting it with an oversize S…

Helical Gears

Helical gears for parallel shafts: the helix angle, normal versus transverse module, why the gradual tooth engagement runs quieter and stronger, the axial thrust it produces, th…

Inch Threaded Fasteners

The unified inch thread system: reading a designation like 1/4-20 UNC, the coarse-versus-fine choice and the stress area that decides it, classes of fit, and the SAE grades and …

Iron and Steel Castings

Making shapes by pouring molten metal into a mould: sand casting and its mould, the shrinkage allowance the pattern must carry, how solidification and Chvorinov's rule govern fe…

Keys and Keyseats

The little block that carries all the torque: the parallel key sized in shear and crush for a Ø40 shaft — and why crushing governs — the taper, Woodruff and feather family, the …

Knurls and Knurling

Rolling a grip pattern into metal: straight, diagonal and diamond knurls, why knurling displaces rather than cuts, the tracking condition that keeps a pattern clean, and the dia…

Lasers

The laser as a manufacturing tool: what makes laser light special, the enormous power density at focus, cutting with an assist gas, keyhole welding and marking, and the differen…