Rockwell hardness tester
- Thread starter Gliden07
- Start date
Don Robinson
Well-Known Member
If it's a bench model, yes, by all means, if you intend to heat treat your blades.
Kevin Zito
KNIFE MAKER
I say that if I had your money, I’d throw mine away... lol. I would definitely get it. The main reason that I use Peters HT is that I “know” the hardness when I get it back. There is no guessing. I also like the fact that I can tell a possible customer that the blade hardness has actually been tested.
I must add, though, that I have no idea what the upkeep is on these machines or the reliability of the results. I’m sure a more educated person will be along soon to shed some light on this issue.
Kevin R. Cashen
Super Moderator
I am not familiar with the 2C unit, but I got a similar deal on my Wilson and I consider it one of the best deals I ever made. The Wilson testers are top of the line and you won't touch one for that price, even used, on the open market. Not only are they very reliable in quality, they are also common enough to be the easiest to get parts and service for, and there will always be demand for them should you want to resell them.
Gliden07
Well-Known Member
It' a Wilson 3JS. Guy tells me it' complete?? Is there anything I should look for as a deal breaker? If it needs recalibration what does that cost?? I've never thought of buying one of these until now and am uneducated on them.
Kevin R. Cashen
Super Moderator
The JS is good one. If by "complete" he means it still has all the weights, then GET IT! The weights are hardly ever still with the units. Does it have a diamond penetrator? It is not a deal breaker but is nice to have to possibly check it out, if you have to buy one they range from $80 to $200 depending on how high a quality you get (i.e. Chinese or brand name). If you do not know it is fully functional, to check it out simply cycle it with the side lever slowly by hand to see if everything moves fine. This is a precaution because if you trip the major load without oil in the dashpot and the penetrator makes contact with anything it could damage it. If there is oil in the dashpot, in other words, the machine cycles gently and slower, then you can fully test it out. If nothing is obviously broken, or rusted up, these machines are very easily adjusted and put back into working order. The most important part is the calibration test block. You can get Chinese knockoffs cheaply, but a good brand name like Wilson or Starr are worth the money. Get one that is in the range that you will be doing most of your testing. Only a couple of times I have seen units that had some more severe issues that required professional repair/calibration, so I wouldn't know how much that could cost, but the majority could be brought back into line with somebody that was mechanically handy who had a manual. The manuals for the JR's an JS' models are easy to find.
Motor City Mike
Well-Known Member
See if it comes with testing blocks. It should if it's "complete"
Do a test on one of the blocks, preferably the C block since that's the scale we generally use.
If it's accurate, pay the man his money and take your new toy home.
If it isn't, I'd check into the cost to have it recalibrated before committing to buy.
opaul
KNIFE MAKER
07.........do exactly what sleestack said and if it works out and is complete. Send me the name and address of the seller and I'll buy it
JK........good luck and hope it works out for you.
bladegrinder
Well-Known Member
I'll add this, I have one that I'm not sure of the model because I'm not there right now but I believe it might be the same one your looking at....and if your somewhere where it's freezing right now testing it might seem a little awkward, I know with mine...and I'm in Florida, when it gets really cold it works a lot slower that normal. I'm thinking it's the oil in the dashpot, so if it's freezing where you are, you might want to anticipate slower than normal results testing it out.
bladegrinder
Well-Known Member
Also... the dial scale on mine is....I believe N scale, that didn't make sense to me when I got it and couldn't figure out what the heck I had here. I called Rockwell and they turned out to be some real nice folks to deal with. they sent me a real nice poster size chart for converting N scale to C.
This wall chart has a BUNCH of different hardness conversions columns. A,B,C, brinell...I think there's even one for bisquits.
This wall chart has a BUNCH of different hardness conversions columns. A,B,C, brinell...I think there's even one for bisquits.
Kevin R. Cashen
Super Moderator
The dashpot should be filled with a 10W10 oil and is adjustable. It is best if you can set up the tester in a location where the temperature will not fluctuate much, as the temperature greatly effects the viscosity of the oil and thus the rate of load application. The timing of load application is rather critical to accuracy of the results. You can adjust the timing by a knurled knob on the top of the dashpot that will increase or decrease the flow of oil through the hydraulics. You want to adjust it so that the rate of load is from 4 to 7 seconds from the time of trip to time of full load application (the needle is motionless again), One other thing to look for in a used unit- are the threads on the elevator clean of damage or rust? That segmented aluminum sleeve is a very important part of the tester, those threads must be kept clean and dust free and lightly oiled or the accuracy of the tester can be greatly affected. To give you an idea of how touchy that can be, when I do my first test of the day, I will put a sacrificial test block in and trip the load to let it just sit there for several minutes before proceeding with calibration or actual testing. What this does is squeeze any oil out of the threads of the elevator and prepares it for accurate testing. If you have doubts of this go ahead and just take a couple of quick reading with your test block at the start of the day and watch how the readings will climb a point or two before it levels off. It is also important to keep the anvil as clean as possible, if there is any rust present lap it down to a shiny finish again.
If the unit really needs actual calibration, you can accomplish this by adding small weights (like washers or coins), on top of the major load weights hanging off the back, until it reads spot on. This is normally accomplished with lead shot added to a cavity that is sealed in the major load weight set, but it is sealed by a riveted plate and often on older units you may need to add more weight than what that cavity can hold. I usually just weight my coin stack and then cast a single lead puck to match it and set it in place.
Quite often used units may need the initial set point at minor load adjusted, there are detailed instructions for this in the manual.
If the unit really needs actual calibration, you can accomplish this by adding small weights (like washers or coins), on top of the major load weights hanging off the back, until it reads spot on. This is normally accomplished with lead shot added to a cavity that is sealed in the major load weight set, but it is sealed by a riveted plate and often on older units you may need to add more weight than what that cavity can hold. I usually just weight my coin stack and then cast a single lead puck to match it and set it in place.
Quite often used units may need the initial set point at minor load adjusted, there are detailed instructions for this in the manual.
The 3JS is a superficial hardness tester and Wilson says it requires a "precision diamond" penetrator. You might want to do some research on this. If you need a new precision diamond penetrator, the cost in 2009 was $500.00.
A lot of the old JS testers were converted to JR testers, you want to look at this very close. If you can post some pictures I might be able to help.
John
A lot of the old JS testers were converted to JR testers, you want to look at this very close. If you can post some pictures I might be able to help.
John
bladegrinder
Well-Known Member
I just got home from a few days in the woods and just looked at mine. it is a 3JS.
I like mine, it works good. thanks Kevin on that calibration with coins on the weights info,
I might need that in the future when I make a move.
I did have this one come from Tennessee to florida in the back seat of a pickup and it held calibration.
I like mine, it works good. thanks Kevin on that calibration with coins on the weights info,
I might need that in the future when I make a move.
I did have this one come from Tennessee to florida in the back seat of a pickup and it held calibration.
Kevin R. Cashen
Super Moderator
It is a good point about the cost of specialty penetrators, but their drawbacks can also work for you, under the right circumstances. I have seen the penetrators for my Wilson MO unit run around $600-$700, but due to most EBayers not knowing what they are I have never paid more than $150. But you do run the risk of not being able to find them. I often don't think about these details when I find another new nerd toy to play with.
Not sure if that takes the same diamond penetrator as the HR150A does or not, but if so, here's a very low cost that will work just fine. OR - the one I ordered does. I wasn't sure if it would work or not so I ordered one to play with. Changing from one to the other didn't seem to change test block reading at all. For $12 it's worth a try.
https://www.ebay.com/itm/252377813774?
https://www.ebay.com/itm/252377813774?
bladegrinder
Well-Known Member
I hope you get it Gliden, you'll like it. and that's a killer price.
here's a picture of my 3JS...
here's a picture of my 3JS...