Search results for query: *

I have received my test results for the microstructure. The lab tested 3 samples. They used a 3% nital etchant and 100X-400X magnification. A cross section was mounted, polished and etched. The examination reveals that all three structures are uniform structures of ferrite and some tempered...

TVP, I appreciate the assistance as well as that help from everyone else who has spoken up in this thread. I will update with results from microstructure and full size double shear test in a few days.

mfgenggear, 1. There are approximately 630 pcs in the lot 2. The parts are turned. The tolerance is +0.000/-.002 6. Good point. I will request that they retest using a proper fixture. If they cannot I will call and find another A2LA lab to do the testing. What section in the Timken Handbook are...

higher cost isn't much of a concern. I have 15K in sellable product stuck in MRB. Making these good parts is the only option.

The lab still has the 13 samples from the double shear. I ordered microstructure evaluation on 3 of those samples. 2 samples are those that had the lowest load at failure during the double shear, the 3 one is the only sample that passed double shear. I should have results in 2 days. In the...

they oil quenched at 144 F

dbooker630, That is a excellent suggestion. I just returned from the heat treater. The hardness results from their facility were chaotic to say the least. The oven charts revealed that the tempering was only held for 45 minutes. The temp was 1075 F. The parts took roughly 1/2 hour to come up to...

I am already scheduled to witness them retesting the parts tomorrow. We are pretty much on the same page. It is possible that the samples they pulled in their test were OK but that other parts of the lot were bad. I just need to have a recovery plan and understand my options when I go there...

IRstuff, Doubtful, I had thought about that but they alter test specimens all the time. It is a fairly common practice in the fastener industry for mechanical testing. The bottom line is my hardness results are deviating by as much as 30% from those listed on the heat treaters certification...

I have a lot of clevis pins that failed double shear test. I am trying to determine if they can be reworked to an acceptable condition. The part is MS20392-12C117. It is a 1" diameter by 3.6" effective length pin, cad plated to AMS-QQ-P-416 Type II, Class 2. Here are the details as the lot sits...

it is obvious that immediate tempering is to reduce internal stresses in the material caused by h/t and quenching. does a second tempering need to occur to reduce stresses induced from cold working the material? in this case thread rolling. i will review the standards recommended with a little...

mfgenggear, My company is producing these studs to fullfill a purchase order to a customer. I do not know the design criteria, just the PO and drawing requirements. The spec only requires a 35HRC maximum hardness. The material is 4140 alloy steel. The annealed hardness is currently 23 HRC...

metenger.... is the tempering step a stress relief that is used after cold working? I have read the ASTM spec six ways to sunday and cannot determine a specific or required sequence. I am basically at a cross roads. Do I thread roll then heat treat with no tempering or do I heat treat, thread...

I am currently reviewing our shop traveler for processing B7 studs. The final configuration of the part is an M12 thread X 4.5 in long with dacromet 320 coating. The parts will be thread rolled in our facility. I am confused as to the proper sequencing of operations to achieve the correct...