Per your suggestion I am bringing this over from CM's thread:
I personally have slobbering love affair with npk and particularly old npk at that 2 of my hammers ar as old as I am another is real close and then the last 1100 pounder that I bought is only about 4 years old and it's no were near as good as my h4xe.
I think NPK makes good hammers. I was also considering one of those when I bought my 5,500# hammer. I looked at your thread and one of the small hammers you had looked pretty old. Not judging by scratches/cosmetics but by the lower casting (where lower bushing would be housed). It almost looks like it is from the "Art-Deco" era. New hammers are expensive (see Cm's last post) and if you can keep that older hammer running well I see no reason to replace it. A new one won't bring you any more per hour.
We mainly run backhoes 416 and 310s for the smaller ones and a 446 for the bigger tho I did just acquire a 314 excavator so I have that for the 7xs now.
I started out with a 416B. The last TLB that I bought is a '97 416C. I bought both new and I still have the 416C. It has about 13,000 hours on it now. I almost bought a hammer for my 416. If I were still in CA I am sure I would be running one. Back when my '97 416C was new I was a bit fearful of what a hammer would do to my pride and joy. Funny thing is I was invited by CAT to go to Peoria and demo the prototype D model 420. While I was being debriefed (by the guy who was responsible for TLBs at CAT) I asked what CAT found to be the attachment that put the most stress on a backhoe. I thought (for sure) that he would say a hammer but he did not. He said that their research indicated that a compaction wheel was the most stressful. I moved to CO before I bought a hammer and ironically I had already been running a compaction wheel (on and off) for a few years.
We used to have a kobelco 210 LC series 2 that was a wore out girl when we bought for like half of scrap it cost double what we paid for it to plumb it and the we hung a 10 x witch is 3500 or 4000 lbs I think we owned that machine for about 6 years and 2000 ish hours and i probably put at least 1200 of them on it never had to fix a thing on that machine we sold it right before in 08 before I got out of high school.
My girlfriend's brother owns a Kobelco 210. He is an owner/operator and I think he said that he has a bit over 10,000 hours in it. He claims that he has had no major issues with it and currently doesn't have any plans to replace it. Your thread showed your dad sitting in a Hitachi 210 with an Okada hammer on it and you did not mention either in your reply. Was that a rental?
As far as rock you get a variety like granite and white granite blue granite both of witch will eat a point fast if your not paying attention then you get all varieties of cleach and last but not least you get malipi witch is pretty much straight lava all this rock comes in a variety of hard ness but my favorite is what we call baby powder rock cause you literally grind it to dust cause it dont break off in any pieces.
As I mentioned in my last post I have something similar in my neighborhood. The "b*****d rock" here is a mixture that the geotech guys call "sandy limestone". What point design do you usually run on your tools? Do you notice that one type works better than any other? I have been running chisel points on mine. It doesn't take long before they are "blunts". I just had one re-chiseld (cut to factory spec by a water-jet cutter) and am anxious to see how it does. I plan to use it tomorrow. Another irony is that the MFR recommends blunt tip for bedrock. I'm not sure if I agree-which is why I'm inquiring.
As far as rock you get a variety like granite and white granite blue granite both of witch will eat a point fast if your not paying attention then you get all varieties of cleach and last but not least you get malipi witch is pretty much straight lava all this rock comes in a variety of hard ness but my favorite is what we call baby powder rock cause you literally grind it to dust cause it dont break off in any pieces.
It can get boring but it pays by the hour it's a good challenge I have taken on quite a few rock jobs others have given up on it makes a challenge sometimes frustrating especially when you wipe out a point but I have never had a machine failure from hammers abusing equipment and at one time dad had 7 of them banging everyday
A new tool for my hammer is only about $1,300 (for OEM). If we run the hammer long enough to wear out a tool I should have also generated enough revenue so that I won't worry about buying another. I bought the hammer and crusher to specialize in rock jobs (as they can be lucrative) so I don't shy away from them either.