An 82° countersink angle is compatible with the profile of flat- and oval-head inch screws; a 90° countersink angle is compatible with the profile of flat- and oval-head metric screws and is … For countersunk holes, counterdrilled holes specify the diameter and the included angle of the countersink. Re: How to measure countersink angles One more thing...there's also often an issue with the block tolerance for angles (typically +/- 1 degree) and measurement of c'sinks.


The following are standard tolerances for general machine work and apply in all cases except where greater or lesser accuracy is required by the design. The basic requirement for countersunk head screws is that the head should fit into a countersunk hole with as great a degree of flushness as possible.

A 100 degree countersink tool can not produce a 98 degree to a 102 degree countersink, in other words, the angle is fixed and can not be adjusted. 53. ietech (Industrial) 3 May 07 13:08 See if this helps --- I Googled for countersink tolerance and got a bunch of choices.

(3) The angle should probably not be basic, unless there is also an angularity or profile callout associated with it, not shown on your drawing. A larger angularity tolerance say 0.5mm allows for your angle to be off by more as well, because the angle can now be larger but still allow the feature to fall within the tolerance zone.

actual depth may vary depending on actual head diameter and angle countersink diameter tolerances are +/- .010 countersink angle tolerances are +/- 2 degrees free should be used unless close is required Many engineers do not fully understand GD&T either, so some of them make all the things basic, (or teeny-tiny tolerance), just to be "safe". Given #1, the DIN spec applies to the c'sink angle …

What this means is that the tolerances of the angle and diameter of a countersink hole are critical to it functioning properly. This tool is designed to produce a specific countersink size at a specific angle. The title block calls for a 30' tolerance on angles, but the nominal 100 degree angles are measuring outside of that. Drilled Hole Size: Tolerance.0135 THRU .125 +.004/ -.001.1260 THRU .250 +.005/ -.001 countersink diameters are based on the theoretical maximum head diameter at a depth of .005 to .015 and an angle of 82 degrees.

There is no direct tolerance on the countersink angles.

FREE Shipping on eligible orders. Tool sharpness, accuracy, tool and machine rigidity, machine spindle bearings wear, general quality of machine, use of drill fixtures, material thermal expansion,

CATIA Functional Tolerancing & Annotation CATIA® V5R19 Geometrical Tolerancing, Page 168 ©Wichita State University The tolerance will appear in the tree as shown below.

in parts having a hardness which approaches, equals, or exceeds the screw hardness.

(3) The angle should probably not be basic, unless there is also an angularity or profile callout associated with it, not shown on your drawing. On an assembly, would countersink fasteners requiere tighter tolerances? The 60° countersink angle is compatible with the profile of centers on a lathe. Countersunk-head screws that follow the Unified Thread Standard very often have an 82° angle, and screws that follow the ISO standard very often have a 90° angle.

Chris Systems Analyst, I.S.

Because fastener performance is so important, countersink tolerances are critical. Hole Alignment Tolerance Stacking Issues Fritz Scholz Mathematics and Computing Technology Boeing Phantom Works February 24, 1999 Abstract Each of two parts has K coordination holes with the intent that each hole on one part is paired and to be pinned with … A countersink, on the other hand, is a functional surface upon which a fastener head bears. In the real world however we find that the sharper, pointier angle on the 90 o gage provides a firmer, more positive feel when inserting the gage in the part.

Figure 18.7 and Table 18.5 give dimensions. I would remove it and just call out the depth/angle.