B.07_Questions_for_Solicitation_W91271N19Q0102.pdf

Response to Questions for

Solicitation W91271N19Q0102

8/7/2019

Question 1: Section 1.1 specifies material to be cold finished. Cold finished rectangular bar stock is not available for this type/size of material. Since perforce all faces of the bars will be machined anyway, can hot rolled material be used? This callout would not be applicable to forged stock, are forgings acceptable?

Hot rolled material may be used. Forged material may be used. Finished product must conform to all other requirements of the solicitation and as noted within these clarifications.

Question 2: Section 1.3 calls for passivation of material if it has been heat treated. Ordinarily passivation is performed after finish machining of the pre-hardened material, not after heat treatment.

Is passivation required for all parts whether heat treated or not?

Passivation should be performed if any portion of the material becomes contaminated regardless of heat treatment.

Question 3: In table 2.1 the term “UNO” is used. What is the meaning of this acronym?

Unless Noted Otherwise (UNO).

Question 4: Section 3.1 calls for government inspection prior to any machining. It may be beneficial for reasons of availability or cost to machine the shoes from round bar stock. Would the inspection take place in the round or after machining the stock to a rectangular shape?

It will be beneficial for the awardee to perform their Quality Control of the material prior to the machining to catch any material that does not meet acceptance criteria. Government inspections in this instance can be performed post-machining, so long as the awardee is aware that any defective material may be rejected by the Government, machined or otherwise.

Question 5: Section 3.2 and sub-paragraphs delineate non-destructive testing specifications for forged and extruded materials only. Is NDT required for hot or cold rolled material? If round bar stock is to be used, and NDT is required, should it be conducted before or after the stock has been machined to rectangular shape?

Yes, NDT will be required for hot or cold rolled material. In this proposed scenario, it may not be feasible to perform NDT efficiently prior to machining due to shape. The awardee may find it beneficial to perform their quality control of the material prior to machining as the Government may reject any defective material, however, the awardee will be responsible to demonstrate compliance with NDT requirements and to deliver a product that is acceptable per the solicitation criteria.

Question 6: Section 3.5 calls for dimensional and hardness testing. Are all 22 shoes to be tested or if a representative sample, what would be an acceptable sample size?

Reference paragraph 3.5.2. The language intends to communicate that the sample size is intended to be per “heat”. Paragraph 1.3 also requires submission of a detailed heat treatment procedure for approval as well as the certified heat treatment reports.

Question 7: Section 3.5.1 calls for dimensional inspection using a CMM. Can inspection be alternately performed using a Laser Tracker? As an August delivery is called for and because many machine shops are not air conditioned and in view of the high ambient temperature being experienced in many parts of the country, the requirement for inspection between 64 and 72 degrees Fahrenheit may be burdensome to this contractor. Can the high temperature limit be waived or raised? Or alternately, can an expansion factor be applied to measurements taken at a higher temperature?

The method for dimensional inspection must be able to verify the dimensions to within the specified tolerances communicated in Tables 2.1, 2.2, and 2.3. A generally available laser tracker does not appear to have the accuracy necessary to achieve verification of stated tolerances. However, dimensional inspection may be performed by alternate means provided the awardee can provide means which will meet or exceed the capabilities required to verify the stated dimensions and tolerances of this solicitation.

Inspection within an ambient temperature environment between 64 degrees Fahrenheit and 72 degrees Fahrenheit is required and will not be waived or modified as proposed.

Question 8: Section 3.5.2 calls for hardness testing. Because of the part size, this would call for the use of a portable hardness tester. ASTM A370 and ASTM E10 standards are cited however commercially available portable hardness testers claim compliance with ASTM A1038 and/or ASTM A956. Would this be acceptable?

Yes, portable hardness testers that comply with ASTM A1038 and/or ASTM A956 is acceptable.