WI-31 WORK INSTRUCTION FOR RAW MATERIAL SAMPLING

Doc. No:  KKM/GWI/31 WORK INSTRUCTION FOR RAW MATERIAL SAMPLING 
Rev.  No.:  01
Rev. Date:   20.11.2012

 

                       TABLE “A” SINGLE SAMPLING NORMAL INSPECTION OF COMPONENT.
S.NO LOT SIZE SAMPLE SAMPLE

SIZE CODE

 AQL AOQL
SIZE Ac Re
1 0002  –  0500 13 0 1 E 1.00 % 2.80 %
2 0501  –  1200 20 0 1 F 0.65 % 1.80 %
3 1201  –  3200 32 0 1 G 0.40 % 1.20 %
4 3201  –  10000 50 1 2 H 1.00 % 1.70 %
Ac : Acceptance Number                                           Re : Rejection Number
NOTE 1 The Inputs For Deriving The Plan in Table “A”(Only NDT) Has Been 

Taken IS 2500:2000 Part 1st at Special Inspection Level S4 Of Table 1st Table 2nd A For AQL & Table 5th A   For AOQL Values.
2 SL.NO 4 Of Table A is not applicable for spark, spot or acid etching

Test. It is limited up to SL. NO3 Only
3 In Case Of Non Conformance The Lot Has To Be Scan 100% For Spark, Spot Test & Cracks. 

 

TABLE “B” (Technology Wise Plan For N.D.T & D.T Test.)
S.No Items Technology Sampling Plan For
N.D.T Test D.T Test (Min)
1. Steel A:- Chemistry ( Spectro ) ——– 2 sample Per Heat
B:- Meta Scope 100 % Rods  ——–
2. Hardening C:- Grain Size ——– 1 sample Per Heat
D:- Inclusion ——– 1 sample Per Heat
E:-Internal Soundness (Macro) ——– 2 sample Per Heat
3. Test Bar F:- Jominy Test ( If Specified ) ——– 1 sample Per Heat
4. Forged & Heat Treated

(If Specified)

 G:- Step Down ( If Specified ) 5 sample Per Heat
H:- Visual Inspection 100 % Rods ——–
K:- Spot Test 100 % Rods ——–
Forging Spark Test AS PER TABLE “A”
Spot Testing AS PER TABLE “A”
Hardness Testing AS PER TABLE “A”

 

Table:- “C”
S.No Lot Size SAMPLE Sample Size Code AQL AOQL Limit Quality
Size Ac Re
1 002 – 150 20 0 1 F 0.65 1.8 11 %
2 151 – 280 32 0 1 G 0.40 1.2 6.90 %
3 281 – 500 50 0 1 H 0.25 0.74 4.50 %
4 501 – 1200 80 0 2 J 0.65 0.48 4.90 %
5 1201 – 3200 125 0 3 K 0.65 1.1 4.30 %
Ac : Acceptance Number                                           Re : Rejection Number 
NOTE: – The in puts for deriving this plan have been taken from IS2500-2000 Part 1st

BACK UP DATA: –

  • Samples Size of 20Code “F” at general inspection level II for lot size up to 150.
  • Samples Size of 32Code “G” at general inspection level II for lot size up to 151 to 280.
  • Samples Size of 50Code “H” at general inspection level II for lot size up to 281 to 500.
  • Samples Size of 80Code “J” at general inspection level II for lot size up to 501 to 1200.

For practical use and considering normal die run 5 categories of lot size have been designed in this sampling plan. S.No 4&5 lot size a little sampling risk has been considered by selecting special level S4 table No-4 of IS2500-2000.                      

  1. Table No. IIA given the AQL Values.
  2. Table No. VA given the AOQL Values.
  3. Table No. VIA given the limiting quality”LQ”.

According to the plans S.No 4&5   ; 1 & 2 Nos. Respectively non conforming have been Accepted considering die wear. In such cases these pieces have to be deviled and acceptability of the lot should be determined by using. The sample plan associated with specified value of AQL depending upon one sided or two sided limits and acceptability.                     

  1. The Value of expression (X+K ” σ “) < U         (one sided limits.)
  2. The Value of expression (X+K ” σ “) > L

   Where x is the mean value of the parameter.

  K” is the specified factor against (n) the sample size for a particular AQI From

    Table No. 2 of IS 2500-1965 (Part ll)

       σ is the variability.

     “U” is upper dimension.

           L” is lower dimension