Industrial machinery parts and components are the standard building blocks of production machines – bearing units, levelling feet, castors, conveyor parts, fasteners, handles and seals – that determine how reliably a machine runs, how easily it is maintained and, in food and pharma plants, how well it can be cleaned. They are bought by machine builders (OEMs) for new equipment and by maintenance teams as replacement parts.
This guide explains the main groups, the materials they come in, how to select them and how to judge a supplier on facts. For the most-searched single component group, see pillow block bearings: the complete guide.
For how hygienic machinery components are manufactured – materials, finishing and passivation – see cutting-edge machinery parts and components.
What industrial machinery parts include
The term covers a wide range of hardware. Grouped by function:
| Group | Typical industrial machine parts | Function | Main selection criteria |
|---|---|---|---|
| Motion | Bearings and bearing units, sprockets, pulleys, gears | Controlled rotation and power transmission | Load, speed, sealing, lubrication |
| Mobility | Castors and wheels | Moving frames and trolleys | Load per castor, floor type, swivel/brake, noise |
| Support and levelling | Machine leveling feet, solid base feet, levelling mounts | Carry the machine, level it, damp vibration | Load per foot, thread size and stem length, articulation angle, fixing |
| Transport | Conveyor belts, modular chains, side guides, wear strips | Move product through the line | Product, speed, friction, cleanability |
| Assembly and operation | Fasteners, knobs, handles, seals | Hold the machine together and allow adjustment | Material, sealing, crevice-free shape |
Two terms used throughout: a harbourage point is a place where residue and microorganisms survive cleaning; a crevice is a narrow gap that cleaning fluid cannot flush. In hygienic industries, every part is judged on whether it creates either.
Industrial machinery components by function
Motion: bearings and bearing units
Bearings, sprockets and pulleys give controlled, smooth movement. A bearing unit combines a bearing insert with a housing (pillow block or flange) ready to bolt to the frame. In wet areas, the housing material and seal decide service life. Ingress ratings help: IP67 (IEC 60529) is an immersion test, not a washdown rating; IP69K (ISO 20653, also written IP69) tests high-pressure, high-temperature water jets. Neither is a hygiene certification. Background: IP67 vs IP69K.
Support: levelling feet and mounts
Levelling feet stabilise equipment, compensate for uneven floors and reduce vibration transmission. Key attributes: load class, thread size and stem length, base diameter and base material, articulation (swivel) angle, and fixing – free-standing or anchored through one or two holes. In hygienic zones, the foot should have no exposed thread. For load calculation and stability, see how machine feet affect stability and vibration.
Mobility: castors
Castors carry mobile frames, trolleys and cleaning carts. Select by load per castor (assume one castor may be off the floor on uneven ground), wheel material versus floor, swivel and brake type, and noise. Stainless castors are used where washdown and chemicals would corrode zinc-plated steel.
The parking mechanisms and support limitations guide distinguishes wheel brakes, steering locks and separate floor-contact devices.
For racks exposed to ovens or cold rooms, check the thermal-cycle specification for rolling supports before choosing an assembly.
Transport: conveyor parts
Conveyor belts, modular chains, side guides and wear strips move and guide the product. Low friction and wear resistance matter, but so does cleanability: open frames, removable guides and no hollow sections.
Assembly: fasteners, knobs and handles
Standard hex bolts, socket screws and knobs create recesses and crevices. Hygienically designed versions use rounded heads and sealing washers – see safe food production with EHEDG components and parts.
At hollow frame ends, the threaded end-fitting and sealing guide separates attachment strength from closure against cleaning-water ingress.
Materials for industrial machine parts
| Material | Strengths | Limitations | Typical use |
|---|---|---|---|
| Stainless steel AISI 304 | Corrosion resistant, cleanable, durable | Chloride pitting in salty or chlorinated conditions | Hygienic frames, feet, bearing housings |
| Stainless steel AISI 316L | Better chloride resistance (molybdenum) | Higher cost | Wet, salty or aggressive cleaning zones |
| Engineering plastics (POM, nylon/PA, UHMW-PE) | Light, low friction, chemical resistance | Lower load and temperature limits; PA absorbs water | Conveyor wear strips, rollers, wheels |
| Carbon steel | Strong and economical | Corrodes without coating; not for wet hygienic zones | Heavy-duty general machinery |
| Aluminium | Light, easy to machine | Attacked by alkaline detergents; softer | Packaging machine frames, profiles |
| Composites and thermoplastic housings | Do not corrode, light | Load and temperature limits | Bearing housings, foot base plates |
Chloride pitting is local corrosion of stainless steel caused by chlorides in water, salt and some cleaning agents. Comparison of the two main grades: AISI 316L vs AISI 304. Mixing dissimilar metals in wet zones can cause galvanic corrosion, where the less noble metal corrodes faster when both are in electrical contact through a liquid.
For food contact, materials must comply with EC 1935/2004 in the EU (plus EU 10/2011 for plastics) and with FDA rules in the US, such as 21 CFR 177.2600 for rubber. Ask for a declaration of compliance – the supplier's written statement that the material meets these rules.
Requirements by industry
- Food, dairy and beverage: hygienic design, stainless steel or approved plastics, sealed bearing units, feet without exposed thread; daily cleaning by foam, high-pressure washdown or CIP (cleaning in place).
- Pharmaceutical and biotech: cleanable, documented components; material traceability and validated cleaning matter as much as the part itself.
- Packaging: conveyor parts, bearing units and castors for speed and uptime; often dry, but food packaging lines may need washdown-suited parts.
- Chemical: materials chosen for the specific chemicals and temperatures.
- Automotive and general manufacturing: precision, load and cost dominate; carbon steel and standard bearings are common.
How to select industrial machinery parts
- Function: what must the part do – rotate, support, move, guide, fasten?
- Load: static and dynamic load, shock and vibration. For feet and castors, divide by the number of supports that actually carry the load, not the number fitted, and add a safety factor.
- Environment: dry, wet or washdown; temperature range; chemicals; product-contact, splash zone (where product or liquid can splash back) or non-contact.
- Cleaning method: dry cleaning, foam, high-pressure washdown, CIP or COP (cleaning out of place).
- Material: from the table above, matched to environment and cleaning.
- Hygienic design: no exposed thread, no crevices, self-draining shapes, suitable surface finish. EHEDG guidance gives Ra ≤ 0.8 µm for product-contact surfaces.
- Documents: datasheet, material certificate, declaration of compliance, and EHEDG certificate or 3-A authorisation for the exact part if required.
Example: specifying feet and bearings for a new vegetable conveyor
Assumptions (illustrative): conveyor frame 600 kg including product, six feet, daily foam cleaning with alkaline detergent and chlorinated disinfectant, splash zone.
- Feet: on an uneven floor assume four of six feet carry the load: 600 kg ÷ 4 = 150 kg per foot; with a safety factor of 2, specify at least 300 kg per foot. Stainless steel, sealed spindle, no exposed thread.
- Bearings: stainless or composite housings with closed covers, seals compatible with the detergent, ingress rating chosen for washdown.
- Material: AISI 316L where the chlorinated disinfectant is applied, because of chloride exposure.
- Documents: datasheets with load ratings, declarations of compliance for food-contact plastics and elastomers.
How to evaluate a supplier of industrial machinery components
Experience, expertise and reputation matter, but judge them through things you can check:
| Criterion | What to ask for | Warning sign |
|---|---|---|
| Product data | Datasheets with load ratings, materials, dimensions | Missing load ratings or vague material ("stainless") |
| Certifications | Certificate number for the exact part (EHEDG, 3-A) | "Certified" applied to a whole range |
| Food-contact compliance | Declaration of compliance per material | "Food-grade" with no document |
| Technical support | Answers to your load, chemical and cleaning questions | Only catalogue references |
| Availability | Stock and lead-time information for spares | No information on replacement parts |
| Quality system | Material certificates, traceability | No traceability for critical parts |
EHEDG certifies specific designs, not companies; 3-A Symbol authorisation follows a Third Party Verification of a specific design. Both are voluntary. ISO 9001 certifies a quality management system, not a product.
What to write in an RFQ
For one-off and custom machines, see bespoke machine builds: standard or custom hygienic components.
- Part function, quantity and installation drawing reference.
- Load per part, with the calculation basis.
- Environment, zone and cleaning method, including chemicals and temperatures.
- Material grade and, where relevant, surface finish (Ra).
- Thread size, stem length, base diameter or shaft size, as applicable.
- Required documents: datasheet, material certificate, declaration of compliance, certificates for the exact part.
- Spare parts and seal kits needed. For keeping these parts running after installation, see optimizing industrial machinery performance.
For an overview of the component groups available from NHK Group, see industrial machinery parts and components.
