Interpretation ID: aiam2793
Nissan Motor Co.
Ltd.
P.O. Box 1606
560 Sylvan Avenue
Englewood Cliffs
NJ 07632;
Dear Mr. Iinuma: This responds to Nissan Motor Company's March 9, 1978, request fo confirmation that section 581.5(c)(9) of Part 581, *Bumper Standard*, does not prohibit deformation of 'hood ledge' sheet metal which is spot welded to the reinforced panel that transfers bumper impact forces from the bumper shock absorber unit to the vehicle frame.; As I understand the function and location of the 'hood ledge' shee metal, it is not a component of the vehicle that is regulated by Part 581. It is not an exterior surface of the vehicle or any of the other components or aspects of the vehicle regulated by paragraphs (c)(1) through (c)(8). It is also not a 'fastener or joint' regulated by paragraph (c)(9). With this understanding, the deformation you describe would not be prohibited by any portion of Part 581.; In a telephone conversation with Mr. Herlihy of this office, you aske if a prior interpretation to Nissan of the limitation on permissible 'dent' had been in error. Section 581.5(c)(11)(ii) states that dent is measured from a reference line 'connecting the bumper contours adjoining any such contact area'. Our December 1, 1977, interpretation to Nissan agreed that the line extends from any two points of contact of the impact ridge following impact, as opposed to contact just preceding impact. You noted a preamble discussion of May 12, 1977, (42 FR at 24058) that suggests a reference line be established across the area of impact prior to impact.; The preamble language you cited was only our suggestion of how manufacturer might establish a reference line for measurement purposes, rather than the 'definitional' line specified in the standard that establishes the dimensions of the dent. I would note that establishing this line prior to impact could greatly reduce the effective area which would qualify for treatment as a dent. For example, in the case of a convex surface the initial point of contact could be limited to the point of the impact ridge.; I would like to make another clarification of our December discussio on this point. While we agreed that the line designated 'D' would be the line specified by the standard, it appears that additional area (lying along the lower slope of the impact ridge) might have contacted the impact ridge during impact. The agency would consider this area to qualify as a portion of the dent area. It is because of such cases, where dynamic events affect the measurement, that the agency suggested the use of paint or another surface contact marking mechanism to measure areas of contact.; Sincerely, Joseph J. Levin, Jr., Chief Counsel