Alternatives to Screw Connections That Won't Kill Your Tooling Budget

Mike KellerScrews are ugly…cap covers to hide screws are uglier.  There are many options for eliminating the need for screw connections in an injection molded part assembly.  Unfortunately, most will send your tooling budget through the roof.  Slides are often used to create snap connections that are completely hidden once the parts are assembled making a very clean, nice looking finished assembly.  This type of connection is used often in mass market electronics such as cell phones where the volumes make the increased investment acceptable.  For lower volume products, the higher investment is harder to swallow because it cuts into your profits.  Here are some options for clean snap or press fits that can be achieved without adding slides to your tools.

  1. Snap options – if the housing does not need to be completely closed, then snaps can be incorporated without slides.  Small openings will be visible on the outside of the parts where undercuts for the snaps need to be formed.  With some planning and industrial design work, the openings can be hidden in plain sight by integrating them into the part’s aesthetics.
  2. Press Fits – Round bosses pressed into hexagonal holes can offer very good holding power without any undercuts.  Mold changes to tighten the fit are very easy to accomplish by removing material from the flats of the hex pins.  So it is recommended to start with very little interference, and then modify the hex pin to tighten the fit.Screws
  3. Partial or full perimeter internal groove feature – with the addition of a stripper plate to the mold, a shallow undercut can be molded around the perimeter inside the part without the need for slides. This undercut can be mated with an external bead on the other part to lock the parts solidly together.

    Here’s a YouTube video on “Stripper Mold Animation” that illustrates this process:

Posted by MAGNET Ohio in General

Most Recent

Top 10 Sited Safety and Health Violations

December 13, 2017 by Gwido Dlugopolsky

One remarkable thing about the list is that it rarely changes.  The order may change but the top cited standards typically don’t change. Top 10 Sited Safety and Health Violations: 501 - Fall Protection 1200 - Hazard Communication 451 - Scaffolding 134 - Respiratory Protection 147 - Lockout/Tagout 178 - Powered Industrial Trucks 1053 - Ladders 305 - Electrical, Wiring Methods 212 - Machine Guarding 303 - Electrical, General Requirements Three of the 10 sited standards are directed at the construction standard (1926) while other fall within the general industry (1910).  It should be noted however that the general industry standard also has fall protection guidelines. Year after year, inspectors see the same on-the-job hazards, any one of which could result in a fatality or severe injury. More than 4,500 workers are killed on the job every year, and approximately 3 million are injured. By understanding these regulations you can improve your safety program and prevent injuries. Give me a call if you have any compliance doubts, or want to review OHSA regulations. Gwido Dlugopolsky at 216-391-7766 or

Complete ANY Changeover in 10 Minutes or LESS

December 11, 2017 by Gwido Dlugopolsky

Why does it take a NASCAR pit crew only 15 seconds to change four car tires when it takes people like you and me minutes? The answer is simple SMED. Single Minute Exchange of Dies, or SMED, is a process for reducing the time it takes to do equipment changeovers. Using the principles of SMED you should be able to perform any changeover in your facility in under 10 minutes! The SMED process is simple – convert as many changeover steps as possible to “external”, meaning they are done while your equipment is still RUNNING, while simplifying and streamlining the remaining steps. SMED is broken down into the following 3 Steps: Separate Convert Streamline We found this article to be very helping in explaining the SMED process in more detail: LEAN PRODUCTION - SMED           A good first step to achieve this level of SMED efficiency would be to run a kaizen event at your facility to standardize (5S) your tools and supplies. Doing this alone will help you achieve 40% to 50% greater efficiency. Once the “low hanging fruit” is gone, you can still reduce setup times another 20% by practicing more advanced SMED principles.

Coffee is STILL for Closers: 3 Things Needed to Close Any Sale

December 07, 2017 by Sam Wasylyshyn

The secret to closing any sale is to reduce uncertainty in the buyer and replace it with confidence in YOU, your PRODUCT/SERVICE, and your COMPANY. Step 1 – Confidence in YOU Someone buying from you wants to be able to fundamentally connect with you on a human level and feel confident that you’re an expert in what you’re selling If you’re selling paperclips, be an expert in paperclips If you’re selling design and engineering related services, be an expert in design and engineering related services Focus on addressing the problem, not the solution….MEANING you already know you have the solution, connect with the buyer by being an expert with the problem he/she is facing. Prove that you know the problem and all aspects of the problem like the back of your hand. Step 2- Confidence in the PRODUCT/SERVICE you are selling Someone buying from you needs to trust the product/service you are selling will solve their problem. It’s your responsibility to deliver a solution and the benefits associated with it. Basically you need to “Hit a Homerun” communicating this message. Tip – Use Success Stories: Share with the potential buyer examples of your product/service solving problems and delivering value for