GB

3.5.3

te

Simplify the wording to more closely match the existing wording in MIL-C-48497A.

The scratch letter defines the largest width of the scratch in accordance with Table 1.

GB

3.5.3

Table 1

te

Binning scratches into classes is appropriate, and is the only practical way to evaluate them visually without magnification. However, when/if they are being evaluated with magnification I think we need the option to allow the actual measured largest width of each scratch to be used in the calculations.

GB

3.5.3

Table 1, col. 3

te

This is a serious step backward from the prior version with "disregard" numbers in microns. It is confusing and not what people who perform inspections want to know.

Change column 3 back to "disregard" numbers in microns.

DA

3.5.3

te

How are you going to determine the widest portion of the scratch if you are viewing it without magnification?

DA

3.5.3

Table 1, col. 3, row 3

te

Error in accumulation

Change "Classes A2 and A" to "A2.5 and A."

GB

3.5.4

Table 2, col. 3

te

This is a serious step backward from the prior version with "disregard" numbers in millimeters. It is confusing and not what people who perform inspections want to know.

Change column 3 back to "disregard" numbers in millimeters.

GB

3.5.3, 3.5.4

Tables 1, 2

ed

Format

Center the information in the columns, use µm instead of um.

FD

3.5.5.1

te

Based on the information given the designation is wrong

Change "D-D" to "E-D."

GB
DA

3.5.5.2

te

This example is fundamentally flawed. You are essentially saying "If the widest scratch permitted on a surface is 15 microns then the widest scratch permitted on the surface is 10 microns."

If the user really can allow 15 micron wide scratches but not 20 micron wide scratches, perhaps that should be stated explicitly on the drawing without reference to this standard.

An alternate example might be "If the widest permissible scratch is a Class C, a 15 micron wide scratch is considered a Class C." However an example is unnecessary, the meaning of the ranges in the table is clear.

GB

3.6

ed

"When imperfections appear that might trigger the rejection" seems awkward. "Controlled imperfections" sounds like "deliberately applied imperfections."

Change to "Imperfections larger than the "disregard" size must be evaluated in terms of quantity and length. This section defines how imperfections are to be accumulated during inspection."

GB

3.6.1

te

It is not clear that S is the maximum allowedclass.

It also seems the rest of the wording of the existing 3.6.1 is being reworded just for the sake of rewording it. It is no clearer than it was, it is less clear.

"…the combined length of the scratches falling within the maximum allowable scratch Class S shall not exceed…Where: N is the number of scratches in maximum allowable scratch Class S...."

GB

3.6.1, 3.6.2

te

Apparently "designated scratch" is being used instead of and to mean "maximum allowable scratch." We haven't explained this anywhere.

Go back to the commonly used and understood term "maximum allowable scratch," or "maximum allowable scratch class."

DA

3.6.2

equations

te

The revised equations are ambiguous.

Change the summation from i=1 to n, where n is the number of scratches to be considered for accumulation.

TT

3.6.2

equations

te

S_maxneeds to be defined.

GB

3.6.2

equations

te

The alternate equations do perhaps make it a little easier to understand, in that the units on both side of the inequality are length (inches, mm, etc.). In the original equations the units on both side of the inequality may bewidth (microns) or may they may bedimensionless (scratch # visibility).

The equations should only be offered as an alternate, not a replacement. There is too much history, prior learning and training material surrounding them to delete them

Offer the equations as alternate ways to express the same requirements, or delete them for having marginal value.

GB

3.7.2.4 (new)

If microscope inspection and evaluation of scratches and digs is being performed, buyer and seller should be allowed to agree to use the actual measured dimension of each imperfection in doing the accumulations rather than binning them into classes per Table 1 and Table 2.

To be supplied.

DA

(new)

The standard does not address sleeks: what they are and how to deal with them. We should provide direction.