1.category

Types : Type A ,Type B

2. Chemical Composition should meet requirements of the  description in Table 1

3. Discrepancy in size is permitted?

Types and acceptable size range should meet requirements of Table 2.

4. Density : not less than 9.2g/cm3

5. Vickers-hardness :  actually measured value。

6. Surface description surface is clean, smooth without any quality defects including over-heated, bubble, crack, split, and badly oxidation. In the working process of finished product, holes larger than 0.5mm in the length and depth is not permitted in the fields of sizing area， while holes larger than 1mm in the length and depth is not permitted in the fields of non sizing area。

Tabe 1

Element		content
Mo		(See Note )
Ti		1.0～2.0
Zr		0.1～0.5
C		0.1～0.5
Chemical element /not more than	Fe	0.0060
	Ni	0.0030
	Al	0.0020
	Si	0.0030
	Ca	0.0020
	Mg	0.0020
	P	0.0010

Tabe 2

types	Dia    D/mm	Acceptable tolerance in Dia	length	Acceptable tolerance in length	Catogory
DM20   DM25   DM30   DM35   DM40	20   25   30   35   40		60～80		Type A
DM45   DM50   DM55	45   50   55		80～110		Type B
DM60   DM62   DM64   DM66   DM68   DM70   DM72   DM74   DM76   DM78   DM80	60   62   64   66   68   70   72   74   76   78   80		160～200		Type B
DM85   DM90   DM95   DM100	85   90   95   100		180～260		TypeB
DM110   DM120   DM130   DM140   DM150	110   120   130   140   150		200～300		TypeB