1、FmERAL SPECIFICATION PLATE, SURFACE, (GRANITE) This Specification was approved by the Coomissioner, Federal Supply Service, General Services Administration, for the use of all Federal agencies. 1. SCOPE AND CLASSIFICATION 1.1 m. This specification covers igneous rock (granite) surface plates for use
2、 in precision locating, layout, and inspection work. It encompasses new certification, recertification in the field, and recertification after resurfacing. 1.1.1 Federal specification coverage. Federal sperL6icationa do not include all styles, grades, and sires of the cammodity indicated by the titl
3、es of the c%xifications, but are intended to cover only those generally used by the Federal Government. 1.2 Classification. 1.2.1 Styles and grades. Surface plates shall be of the follbwing styles and grades. Style (Shape) : Style 1 - Rectangular, no lip (see fig. 1). Style 2 - Rectangular, 2 lip, e
4、ither direction (sea fig. 2). Style 3 - Rectangular, 4 lip (see fig. 3). Style 4 - Round, no lip (see fig. 4). Grades : Tl!-V-121 - Varnish, Spar, Water-Resisting. PPP-B-1055 - Barrier Material, Waterproofed, FlexibBe PPP-B-601 - Boxee, Wood, Cleated-Plywood. PPP-B-621 - Boxes, Wood, Nailed and Lock
5、-Corner. PPP-B-636 - Box, Fiberboard. PPP-B-665 - Boxes, Paperboard, Metal-Stayed (Including Stayed Haterial). PPP-B-676 - Boxes, Set-up, Paperboard. PPP-C-650 - Grates, Wood, Open and Covered. Federal Standards: Fed. Std. No,. 123 - Marking for Domtetic Shipment (Chi% Agencies), (Activities outside
6、 the Federal Government may obtain co,G.d at threecqually spaced positions 0n.a circle with a radius of approximately O.? radius of the plate meas:?r= from the-center of the base surface (see figure 6). r STICKER REPLACEABLE FIGURE 6. Support layout for round surface plate. 5 Provided by IHSNot for
7、ResaleNo reproduction or networking permitted without license from IHS-,-,-GGG-P-4b3C 52 m 7737774 004487b T m 3.2.6 Holen, rlotr. and inrertr. Holes, rlots, and imertr, when required, rhall not deform or rtrerr the work rurface (ree appendix 60). 3.3 Work surface. 3.3.1 Workmanship of work surface.
8、 The work surface hall be fine precision lapped, free frm rough lapping marks, and objectionable 8CratChes for the work surface area, (see 3.3.4.2). Evidence of loosely bound crystals on the surface of grade M plates shall be cause for rejection. When periodically cleaned with soap and water or any
9、other noncorrosive cleaner, the work surface shall have a quality of negligible rtickiness when in contact with clean precision objects. 3.3.2 Surface texture. The surface roughness, average of five readings shall not exceed 32 micro- inches arithmetical average for grade AA and A plates and 64 micr
10、oinches arithmetical average for grade B (see 4.5.4). TO prevent sticking and pennit.free sliding of workpieces and accessories, the surface rough- ness shall not be less than 16 microinches. 3.3.3 Tolerances on repeat reading measurement. Tolerances on repeat reading measurement, when the work surf
11、ace is scanned with the repeat reading gage, are given in table II (see4.5.5 for test procedure). If the smallest tolerance is required, specify it on invitation for bid, contract or order (see 6.2(m). If it is intended that small objects be measured on large surface plates, it should be noted that
12、a larger tolerance in flatness over small areas is pennittpd on larger plates. TABLE II. Tolerances for repeat reading of measurement Diagonal or diameter range Inches Thru 30 Over 30 thru 60 Over 60 thru 90 Over 90 thru 120 Grade Grade Grade AA Full indicator movement (FIM) microinches 35 60 110 45
13、 120 70 60 80 160 75 100 200 A B When not specified Over 120 thru 150 25 All sizes 280 140 100 Over 150 240 120 90 When 100 50 specified 3.3.4 Flatness tolerance. All points of the work surface (as measured with .375-inch diameter flat contacts or probes) shall be contained between two paralle1 plan
14、es, the base plane and the roof plane, separated a distance no greater than that specified for the respective grades. The enveloping planes shall bf! parallel to the reference plane (see figure 9). The work surface flatness tolerance for the three 4 times respectively, those of grade AA. Listed valu
15、es in table III do not necessarily comply with formula grades of plates are given in table III and 3.3.4.1. The tolerances on the A and B grade plates are 2 and in 3.3.4.l because they conform with commercial practice. 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without li
16、cense from IHS-,-,-GGG-P-463C 52 W 7777774 0044877 I W Inches k2 12 18 18 24 24 24 36 36 . 36 36 48 48 48 48 48 60 72 72 Round pl 12 18 18 24 24 36 48 36 48 60 72 48 60 72 96 120 120 96 144 :es - diametel 12 18 24 36 48 50 50 50 75 7s 100 150 150 200 250 300 200 300 350 . 500 700 750 600 1100 50 50
17、75 100 125 1 99 199 190 150 150 200 300 300 400 500 600 400 600 700 1000 1400 1500 1200 2200 100 100 150 200 250 2iri 2 )r) 299 3r1q 399 $99 600 600 800 1000 1200 800 1200 1400 2000 2800 3000 2400 4400 200 200 300 400 500 3.3.4.1 Flatness tolerances for unlisted surface plate sizes, The flatness tol
18、erances for unlisted grade AA plates are obtained from the following formula: D 2 Total flatness tolerance in microinches = 40 + - 25 3.3.4.2 Working surface area. The flatness tolerance shall not include the surface along the edge of each size plate as specified in table IV. TABLE IV. Restrictions
19、on eurface area for flatness tolerance - all values in inches 12 thru 48 over 48 1.5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3,4 Gtneral vorhncfi. 3.4.1 Surface plater covered by this rpecification aha11 be nev or resurfaced and of the qualit
20、y 3.4.2 Edger and corners. The vork rurface edges atrd corners shall be approximately 0.2-inch radius for necesrary to produce gocd appearance. plater one foot in diameter or length and 0.1-inch radius larger for each additional foot in sre up to 0.5-inch maximum radiw. All other edges and corners s
21、hall be rmothly rounded. 3.4.3 Sides adjrcant to work surface. ledge surfaces and squareness. The four rides adjacent to work rurface and all ledge surfacer shall have a surface texture such as is comercially produced by a wire saw cutting operation or better and shall be square with each other with
22、in 0.06-inch per foot, 3.L.4 Bottom rurface. Bottom rurface may have a surface texture as rough aa is comaercially produced by a gang rau or *qual. 3.5 Nameplate und replaceable sticker. 3.5.1 Nameplate. The nadeplate shall be permanent and withstand.washing with surface plate cleaning rolventr. 3.5
23、.2 Location of the replaceable rticker. 3.5.2.1 Rectangular plater. The replaceable sticker shall be located on the side nearest to the single rupport pad (ree figure 5). 3.5.2.2 Round platell_. The replaceable sticker shall be located on the side neatest a support pad (see figure 6). 3.5.3 Informat
24、ion on nameplate. Unless otherwise specified (see 6.2Cf) the fOllOWing information shall be permanently and legibly marked: thnufacturers name. Hanufacturers serial number and grade. 3.5.4 Information on replaceable ticker at time of certification. Platnerr tolerance or maximum flatnesr deviation in
25、 microinches Full indicator movement of repeat reading gage in microinchem. Calibration thermal gradient and whether the higher temperature is at the top or bottom of plate. Porition dimcnsionr from edge or edges for key points and secondary points. Method of calibration. Date of calibration and ide
26、ntification of certifier. 3.6 Covers. When specified (nee 6.2(i) the surface plates shall be furntshed with properly fitted masonite, durable wood, plywood covers or other suitable materiel to protect :he work surface when plates are not in.use, The cover shall le so deaigned as to protect the edges
27、 as well as the work surface. Each maronite or wood cover shall be given at least two coats of varnish conforming to TT-V-121 or such pint as rpecified. 3.7 Seam and color streakr. Seams (see 6.3(v) are cause for rejection. Color streaks have no effect on the rcrviceability of the granite (see 4.5.8
28、) and are acceptable. 3.8 sificate of conformance. All plates shall be furnished with a certificate of confomance which rtater that the plate meets the requirements of W-P-46% and which gives the rock type and an average value for the modulus of elasticity. 3.9 Report on flatners calibration. When a
29、lor. The surface plate color shall be the natural granite color, unless otherwise speclfied (tee 6,2(n). 8 Q Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection. =less otherwise specified
30、in the contract or purchase order, the aupplier is responsible for the performcnce of all inspection requirements as specified herein. Except otherwise specified, the supplier may utilize his own facilities or any conmercial laboratory acceptable to. the Government. The Government reserves the right
31、 to perform or have performed for it any of the in- rpections set forth in the specification to assure that sup,plies and services conform to prescribed re- quirementa. 4.1.1 Inspection of materiale and components. In accordance with 4-1 above, the supplier is responsi- ble for ineuring that materia
32、ls and components used were manufactured, tested, and inspected in accordance with the requirements of referenced subsidiary specifications and standards to the extent specified herein, or, if none, in accordance with this specification. 4.2 Inspection by dimensional metrology laboratories. When spe
33、cified (see 6,4.1.), surface plates shall be delivered to the Government or cwmercial dimensional metrology laboratory designated in the contract or order for the tests and inspections specified in 4.5, or elsewere in the contract, prior to acceptance. 4.3 Sampling procedures. Sampling procedures sh
34、all be in accordance withMIL-STD-105. Data for sampling shall be as stated in table V. The sample unit shall consist of one surface plate. FABLE V. Sampling data Category level Visual examination Dimensional examination Testing: Group A Group B Reparation for delivery one S-2 contaher Acceptable qua
35、lity level (AQL) Major 2.5 Minor 6.5 6.5 1.5 1.0 4. O AQL expressed in tem of Percent defective Percent defective Percent Percent defective defective Defect per unit Reference 4.4.1 4.4.2 4.5.1 4.5.2 4.6 4.4 Extunination. 4.4.1 Visual examination. Each samplt? unit shall be examined for any nonconfo
36、rmance in design, mnterial, worlauanship and marking. Defeecs are listed in table VI. TABLE BI. Classification of defects Catenorv None defsned Critical Defects Maior 101 Evidence of chips, fractures, seams, rough edges 102 . Style or sfze not as specified. and rough lapping marks. 103 Support pads
37、not as specified. 104 Marking: %nufacturers name, serial number or 105 Manufactur.xs report of calibration or certifi- cate ob conformance if required, missing. informaedon on replaceable sticker. missing. 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IH
38、S-,-,-I dimensional requirements of 3.2.2 and 3.2.4. 4.4.2 Dimensional examination. Each sample ser,t $hall. he exaoined or any nonconformance with I 4.5 Testing. Each sample unit shall be tested in accordance with 4.5.1 through 4.5.8, without damage to working surface except if seam exists, in acco
39、rdance with the established procedures of the laboratory making the test. The temperature gradients that occur in the plate create significant distortion (see appendix 80). This thermal distortion is included in the calibration for flatness. Therc-fQre, for the calibration to have significance the p
40、late should be maintained at the sane themal cunditi3n as when cali- brated. If these conditions are kept alike within the limits expressed in table VII, the flatness dis- tortion will not exceed one-half of the tolerance given in table III. It is realistic to aatch the antici- pated thermal gradien
41、ts of the air at the level and position the plate is to occupy. Also, local thersal gradiente can be reduced by not mounting on the surface plate those calibrating instruments with built-in heat sources. Aft then dry it off. ff the streak remains wet or damp, it is a seam. If the results are still q
42、uestionable, proceed with the following test: Support the surface plate on a strip of wood under the center line of the streak. Upon two strips of wood, one on each side of the streak, as remote as possible from the streak support a load of 200 lb for each square foot of surface area. This load is t
43、o be central to the two supports. If the plate breaks the mark was a seam or crack. 4.5.9 Flatness calibration and referee test. The eight-line (four sides, two diagonal and two ortho- gonal center lines - see figure 8) grid pattern shall be used in calibrating a surface plate whenever the test.resu
44、lts from sections 4.5.5 and 4.5.6 are challenged. The reference plane passes through the inter- section point of the diagonal profiles. The intersection point is arbitrarily set to zero and the refer- ence plane ir balanced equal distant from the end points of the diagonal profiles. The data points,
45、 11 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-equally spaced for each profile, shall be selected so that one exists at the middle of each profile line. The elevation of each data point shall be reported with respect to the reference plane and r
46、ecorded on the eight-fine pattern. The maximum vertical displacement (+) upward above the reference plane locates the roof plane and the maximum vertical displacement (-) downward below the reference plane locates the base plane (see figure 9). When atepping off the profile lines rigid triangulation
47、 shall be adhered to and the intersection points of all lines shall fall within a 0.3-inch diameter circle of each other, therefore, adjustable pad spacing sleds ahall be required for the diagonal profile I-UM if fixed pad spacing sleds do not meet the requirements for precise triangulation. The min
48、im number of steps per profile run shall be 6, the.maximum rtep spacing shall be 12 inches and the number of steps shall always be an even number. The contact probe or the two pads on the sleds which trace the profile line shall be 0.375-inch in diameter with rharp (not beveled) edge. The outrigger
49、pad on sleds may be a minimum of 0.375-inch diameter or dimensioned approximately 0.4 x 0.5 inches for uniform pad wear (see figure lo), A rimilar rptem of diagonals, perimeter and center linea may be calibrated on plates, and especially on rmall ones, by using a precision calibrated rtraight edge, adjustable supports and a auitably mounted indicator or by using the in-line flatnesr gage with master flat or straight edge for zero setting the indica
