Basic Considerations

In order to produce a piece from lost-wax in the foundry,
it is necessary to consider the following :

• Avoid sharp edges and corners

• Obtain orifices, it is necessary to consult the table shown below

• Place the ribs or reinforcements on the walls which have
weak thickness, in order to break the large flat surfaces

• Put the connection radius between the large and thin sectors.

HOLES AND CAVITIES
Diameter, Length, Depth (mm)
ø	Depth Open Holes	Depth Blind Holes
2 ÷ 4	1	0,6
4 ÷ 6	2	1
6 ÷ 10	3	1,6
> 10	4	2

 

Dimensional Considerations

The dimension should be taken from the geometric centre of the piece. This will :

• Ensure a common method of control by using the same reference point

• Improve the difference in tolerances

• Obtain a correlation between the control equipment and the actual tools.

Tolerance technical data

SIZES

mm Inch

>1 <3 > 0,04 < 0,11

>3 <6 > 0,11 < 0,23

>6 <10 > 0,23 < 0,39

>10 <18 > 0,39 < 0,66

>18<30 > 0,70 < 1,18

>30 <50 >1,18 < 1,96

>50 <80 >1,96 < 3,14

>80 <120 >3,14 < 4,72

>120 <180 >4,72 < 7,08

>180 <250 > 7,08 < 9,84

>250 <315 > 9,84 < 12,40

>315 <400 >12,40 < 15,74

>400 <500 >15,74 < 19,68

LARGE JS15

mm Inch

±0,20 ±0,007

±0,24 ±0,009

±0,29 ±0,011

±0,35 ±0,013

±0,42 ±0,016

±0,50 ±0,019

±0,60 ±0,023

± 0,70 ±0,027

±0,80 ±0,031

±0,925 ±0,036

±1,05 ±0,041

±1,15 ±0,045

±1,25 ±0,049

NORMAL JS14

mm Inch

±0,125 ±0,004

±0,15 ±0,005

±0,18 ±0,007

±0,215 ±0,008

±0,26 ±0,010

±0,31 ±0,012

±0,37 ±0,014

±0,435 ±0,017

±0,5 ±0,019

±0,575 ±0,022

±0,65 ±0,025

±0,70 ±0,27

±0,775 ±0,030

TIGHTENED JS13

mm Inch

±0,09 ±0,0035

±0,10 ±0,0039

±0,11 ±0,0043

±0,135 ±0,0053

±0,165 ±0,0064

±0,195 ±0,0076

±0,23 ±0,0090

±0,27 ±0,0106

±0,315 ±0,0124

±0,36 ±0,0141

±0,405 ±0,0159

±0,445 ±0,0175

±0,485 ±0,0190

FLATNESS

IN FUNCTION WITH THE CONFIGURATION OF THE PIECE : From 0,05 to 0,12 for 25MM (From 0,0019 to 0,0047 for 0,984 INCH)

CONCENTRICITY

< 6 MM : ± 0,075 ; 6 < C < 12,5 = ±0,1 ; > 12,5 : ±0,25 < 0,236 INCH : ± 0,0029 ; 0,23 < C < 0,49 = ±0,0039 ; > 0,49 : ±0,0098

CIRCULARITY

ANGULARITY

ANGULAR TOLERANCE ± 30’

RUNEVENESS

Ra = from 2 to 3,2 µm (micrometer)

TOLERANCE FOR THE WALLS ±0,25 MM (±0,001") minimum