Importers often ask engineers to “make it rugged,” only to discover late in production that products still crack or fail after knocks and drops. In this episode, we explain IK ratings (impact resistance in joules) and show how to convert vague requirements into measurable specs, sensible materials, and pass/fail criteria your factory and inspectors can actually follow.
Listen to the audio here or on Apple Podcasts · Spotify · Amazon Podcasts · Deezer · iHeartRADIO · TuneIn.
What We Cover
- 00:00:12 – Introduction: designing for toughness via IK rating
We frame IK ratings as the practical way to express impact resistance in joules so teams can design and test against it. - 00:01:58 – IK vs IP: ingress ≠ impact toughness
We clarify that IP protects against dust/water while IK covers mechanical shocks, and you must specify both. - 00:05:16 – What is IK? Impact energy (J); Izod/Charpy context
IK ratings relate to energy at impact; we reference pendulum tests to explain brittle vs. ductile behavior. - 00:08:33 – IK scale overview: IK00 → IK10 (~20 J)
A fast tour of the ladder so you can map real-world knocks to a target energy level. - 00:10:15 – Low-impact examples (e.g., light switches)Domestic/office products usually sit around IK05–IK06, where cost and aesthetics still dominate.
- 00:17:02 – Mapping joules to IK (≈0.35 J to 20 J)
We translate common abuse events into energy numbers so your spec is tied to physics, not adjectives. - 00:25:51 – Designing for IK: thickness, ribs, radii
Impact resilience improves dramatically with localized wall thickening, smart ribbing, and generous corner radii. - 00:35:16 – Key takeaway: IK is a system rating
Passing IK depends on the full stack—material, geometry, molding, assembly, and conditioning—not a single datasheet. - …and much more. Listen to the episode for the full story!
Typical Mistakes We See
- Writing “rugged” without naming an IK level.
- Selecting a material and assuming the product will pass IK.
- Hitting the wrong impact locations (e.g., not testing near latches or bosses).
- Skipping environmental conditioning even though the product will see cold, sun, or solvents.
- Testing a single sample and declaring victory.
IK Ratings FAQs
- Q: If the enclosure is PC/ABS, will we pass IK09 automatically?
A: No. Geometry and weld-line placement often dictate the result as much as the resin. - Q: Do we need to do IP tests again after IK?
A: If water ingress is a concern, plan a post-impact IP check, especially around gaskets and seams. - Q: How many samples should we plan for?
A: Enough to expose variation (materials, molding, assembly). A small pilot run is almost certainly cheaper than serious field failures.
Further reading
- Power Tool Plastics (ABS vs PC/ABS vs PA66-GF)
- Plastic Enclosures for Electronics Projects (Plastics Sourcing Guide)
- What type of reliability testing is helpful pre-production?
- How Many Samples To Test for Reliability & Compliance
- Do You Need a Customized Reliability Test Plan?
- Drop Testing: 3 Tests That Can Save You Money
- How Reliability Testing Is Critical To Obtaining Great Mass-Produced Products
- Test To Failure: Why You Need This Reliability Test
- How Many Prototype Iterations & Tests Do We Need?
