Hello everybody,

Hope all of you are doing good and staying safe.

I would like to ask that if our machine has automatical shot classifier, I must check the shot size test in process of shot peening or not ?
Thank you.
Yes. You must separately check the media. In the event that your on-machine classifier has a hole in a screen or other problems, you will detect it with a separate test.
Hi Jack,

Thanks for your feedback.
I will add to Jack's answer: While you still have to conduct media inspections, the required frequency is extended.

An example that I give in trainings is an average sized cast steel shot would have to be inspected every 8 hours of machine operation without classification. Adding a classifier stretches that out to every 40 hours of machine operation (5 times longer). As Jack said, it's done to make sure the classifier is operating properly.

Having a simple screen classifier really ups the game in media quality. Question: What do you currently do when your media fails inspection? Throw it away, or sent it out to be classified by a third party?
While AMS2430 does differentiate between a machine with a separator and one without. (see page 13 table 1) Many older specifications do not. The sample frequency is generally shorter like 2 hours for glass and 8 for steel or conditioned cut wire. However, this is not hours of the day. It's measured in actual time used. Something else to consider is although not discussed in any specification peening media wears out with use not idle time in the machine. So it's really about how many impacts a particle of shot endures. Think of it as how long does it take for all the media in the machine to be used? A small machine would cycle all the media at faster rate than a large machine generally.

1) Review the specification you're working to what does it say?
2) Collect data, I would start at every 8 hours of use for cast steel or CCW.
3) Analyze the data. If good you can probably push the inspection frequency out. (get approval to do so)

Ask yourself is it worth going out to 80 hours between inspections? What if after 80 hours you found the media was no good? How many parts were processed since the last acceptable test? All of these parts would now be suspect and would need to be identified as potentially non-conforming.

Walter A. Beach
Vice President
Hydro Honing Laboratories, Inc.
d/b/a Peening Technologies of Connecticut
8 Eastern Park Road
East Hartford, CT 06108

860-289-2134 Fax

Question: What do you currently do when your media fails inspection? Throw it away, or sent it out to be classified by a third party?

Hi Dave,
We are still in initial set up for new shot peening machine. We think about to send fail media to a recycling company. We have not thought about classifying again by a third party yet. Here in Viet Nam, the shot peening industry is really new and as i know, it just developes in the last 10 years around. There no have any third party here to the classification for steel shots. We need to send out to another part of the world like US or Sing. But again we need to compare which one is more economic.
There are some companies here that do shot peening follow international standard. But it's really hard to approach them to share their technology because of business secret and competity.
Almost knowlegde about shot peening we learn from the internet, international standard and especially in this shotpeener forum.

Thank you.
Hi Walter,

Thanks for teaching me a lot.

Not any actual part done yet. We are in process of initial setting up the machine and working procedure.
From your advice in this thread, i think i should buy a sieve shaker and some screens for testing the quality of media in process of shot peening.

Our customer still uses Mil–S–13165C, Shot Peening of Metal Parts. We also follow this specification to set up our shot peening process.

Do Nhan
Technical Staff
Pioneer Drilling Co.,ltd
Ho Chi Minh City, Viet Nam
I wanted you to know the option of screening the media outside of the machine. If not by an outside company, you may consider investing in a stand-alone screen separator for yourself. Some companies with multiple peening machines do this to avoid putting one on every machine.

Best of luck. Let me know if you need training in Viet Nam. It would be nice to visit there again.
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