- Joined
- Sep 1, 2023
- Messages
- 76
After using home ground HSS tools for a while, I recently got a carbide boring bar, and was impressed by the results, so it led me to get a set of holders.
After doing some reading, I chose to avoid negative rake tools, and I noticed that most of the cheap sets had more or less the same insert types, and got a set of 7 holders, for parting, threading, boring, etc.
The reasoning for going with a cheap set, was that tool holding only has to have the correct geometry within an accuracy well within the capabilities of Chinese mass production, and provided that the metallurgy and hardness info is advertised and decent, it can be believed.
And finally that for certain types of "commodity" tools, the main downside is that you (the customer) has to do the quality assurance, which means that in the worst case, you return the tool at no cost.
I received the tools yesterday, and found a "quality assurance" issue: one of the tools had the insert screw hole off position by aprox half a millimetre, the screw hole misalignment prevents the screw from entering it's hole when the carbide insert is in place.
So, I returned the set, but now I'm wondering if my initial assumptions that led me to "go cheap" on carbide tool holders were correct:
1. are the tolerance requirement for tool holders "loose" enough that "bad ones" will be noticeable by "basement/weekend machinists" like myself ?
2. can the advertised metallurgy info be trusted (42CrMo in this case) ?
Clearly one of the tools in the set was out of tolerance, but the others looked pretty good to the eye: when the inserts are placed, there is no movement possible.
So I'm trying to decide if I should order a new "cheap" set (perhaps from another supplier), or if my assumptions are wrong and tool holders is not an area to go cheap.
After doing some reading, I chose to avoid negative rake tools, and I noticed that most of the cheap sets had more or less the same insert types, and got a set of 7 holders, for parting, threading, boring, etc.
The reasoning for going with a cheap set, was that tool holding only has to have the correct geometry within an accuracy well within the capabilities of Chinese mass production, and provided that the metallurgy and hardness info is advertised and decent, it can be believed.
And finally that for certain types of "commodity" tools, the main downside is that you (the customer) has to do the quality assurance, which means that in the worst case, you return the tool at no cost.
I received the tools yesterday, and found a "quality assurance" issue: one of the tools had the insert screw hole off position by aprox half a millimetre, the screw hole misalignment prevents the screw from entering it's hole when the carbide insert is in place.
So, I returned the set, but now I'm wondering if my initial assumptions that led me to "go cheap" on carbide tool holders were correct:
1. are the tolerance requirement for tool holders "loose" enough that "bad ones" will be noticeable by "basement/weekend machinists" like myself ?
2. can the advertised metallurgy info be trusted (42CrMo in this case) ?
Clearly one of the tools in the set was out of tolerance, but the others looked pretty good to the eye: when the inserts are placed, there is no movement possible.
So I'm trying to decide if I should order a new "cheap" set (perhaps from another supplier), or if my assumptions are wrong and tool holders is not an area to go cheap.