Been away from this issue for a few days.
I don't know the designer personally but thus far I am far from impressed. I tend to blame a lot of these problems on blind reliance on title block tolerances, poor GD&T knowledge (I don't claim to be an expert), a rush to get things done, and my old...
Going to try to upload dummy image to protect customer & employer but the basic concept is illustrated. I stripped all info except what applies so you might have to refer to my OP for some details.
Using this example my understanding is that the 1.000 +/- .015" applies to the entire width of...
I have a customer drawing. The part is basically a rectangular block with all edges shown at implied 90 degree angles. All tolerances are defined in the title block and ASME Y14.5-1994 is referenced in the title block. The width, thickness, and length of the part are dimensioned leaving it to...
I admit I am a bit stumped. Probably not enough coffee yet!
I am working on a part that has a serrated end (DIN serration). The other end of the shaft has two flats milled on opposite sides of the shaft (flats are parallel).
The issue at hand is that the serration needs to be oriented WRT the...
I have had to deal with the differences between the ISO and ASME systems for a long time. I find that having the standards and studying them helps but applying them here in the US doesn't seem to work well. The two systems have fundamental differences that can result in problems. This seems to...
I think I was/am incorrect in a previous post. The flatness specification does refine the size limitation as others indicated. I should have thought more about my response before posting, my (big fat) mistake.
Sorry if I caused any confusion!
I might be mistaken but it sounds like you are checking parallelism not flatness.
We typically check flatness with an indicator on a height gage. The part is supported on the surface in question (this is a must) and we zero the indicator at one point on the surface. The entire surface is...
I do not have the luxury of manufacturing engineers and our manufacturing folks either refuse to develop this information or aren't capable of doing so. If we don't spell out every detail for them the entire system grinds to a halt. Sucks but true.
To resolve the issue I need to include limits...
I am working on the design of a machined casting. Tertiary datum used to position some machined features is a cast hole. I think it is appropriate to use tertiary at MMC but I do not want to add the cast hole size and tolerance to the machining drawing unless I can't avoid this.
Currently we...
I work for a company headquartered in Germany, they invoke ISO 2768 on all drawings. I have version dated 1989-11-15. Man is this standard a pain in the butt.
There are two sections of the standard, 2768-1 deals with "tolerances for linear and angular dimensions without individual tolerance...
4140 is still in the running, as is 8620. The parts need min yield of 116 KSI, so 4140 must be hardened.
Parts are stamped and formed (nothing extreme) prior to hardening so distortion due to hardening process is likely to be a problem.
It is possible that the hardness of the A514 is already...
Attempting to replace a European mtrl specification with something commercially available in the USA. ASTM A514 has been suggested due to the fact that the required mechanical properties of ASTM A514 are within spec.
However, the original design required some sections to be induction hardened...
Still dragging my feet on this but won't be able to for much longer.
It is a no-win situation. Drawings reference a standard for conformance and testing of the material. The specification is clear enough that anyone should be able to get the standard. Vendors quoted the part and the pricing...
I checked a drawing the other day that had 5-6 machined diameters all on the same centerline. There is no specification concerning coaxiality of the diameters on the drawing. Without some sort of coaxiality control (either position or runout) on these diameters I feel that the drawing is not...
I have been instructed to send a copy of an industry standard to a vendor. The problem is that there is an obvious statement on the document that it is protected by international copyright law and is not to be distributed, copied, etc.
I really don't want to do this and I have been dragging my...
