UGIMA® 4305 is an improved machinability austenitic stainless steel developed by Ugitech to offer very good machinability up to 500 m/min with a 25-45% increase in productivity over standard grade 4305. It has the same properties as 4305 but with significantly better machinability due to a controlled inclusion population. UGIMA® 4305 can be welded by common arc and other welding processes and offers good corrosion resistance, though not for marine environments.

1. UGIMA®
4305 – UGIMA®
303
Chemical analysis
C Si Mn Ni Cr Cu Mo P S
≤0.07 ≤0.75 1.5-2 8.0 – 9.0 17.0 - 18.0 ≤0.75 ≤0.5  0.040 0.25-0.33
Typical analysis in %
23-10-2012 – REV00
Although Ugitech takes special care to check the accuracy of the information printed here, it cannot guarantee that this information is accurate, reliable, comprehensive and reproductible as such on its
customers' premises. Ugitech disclaims all responsibility for the use of the data indicated above and invites you to contact its Technical Assistance Department for a specific study of your needs.
General
presentation
UGIMA
®
4305 is an improved machinability stainless steel manufactured only by Ugitech.
Its properties are in every respect identical to those of UGI 4305, except for its machinability, which is quite
exceptional:
 UGIMA
®
4305 belongs to the large family of UGIMA
®
machinability grades, which is a market reference.
 UGIMA® 4305 offers very good machinability up to 500 m/min in turning with a coated carbide insert.
 Productivity increases of 25% to 45% over grade 4305, the current market standard, have been
obtained.
Safety measure:
UGITECH recommends the use of non-resulphurised steel grades for thin-walled components used under
high-pressure conditions.
Classification Improved Machinability Austenitic Stainless Steel.
Designation
Material no.
Europe USA Japan
EN ASTM AISI JIS ISO (ISO15510)
1.4305
X8CrNiS18-9
UNS S30300 303 SUS303 4305-303-00-I
X10CrNiS18-9
UGIMA
®
4305 conforms to the following standards:
 EN 10088-3 : 2005
 ASTM A 314 - ASTM A581/581M - ASTM A582/582M
 AMS 5640 – type 1
 QQS 764 - SAE J405
 JIS G4303 and G4308 JIS SUS303
Mechanical
properties Rp0.2% Rm A Z
Condition (MPa) (MPa) (%) (%)
Without work hardening 200 / 350 570 / 700 45/70 50/80
Work-hardened by drawing and/or
condition +C700 or +C800 EN 10088-3
400 / 700 670 / 950 20/45 20/65
(Values given for information only.)
Cannot be hardened by heat treatment. Can be significantly hardened by cold working.
Physical
properties Density
Elasticity
modulus
Thermal
conductivity
Linear expansion ratio Electrical resistivity at 20°C
(GPa) (W/m.°C) at 20°C ( /°C) between 20°C and 200°C (µΩ.mm)
7.9 196 15.3 16.8 x 10-6
730
Weight of round bars
(in kg/m)
Weight of hexagonal bars
(in kg/m)
Weight of square bars
(in kg/m)
0.0062 x D2
(D: mm)
0.0068 x D2
(D: mm)
0.0078 x c2
(for information only)

2. UGIMA®
4305 - UGIMA®
303
Chemical analysis
C Si Mn Ni Cr Cu Mo P S
≤0.07 ≤0.75 1.5-2 8.0 – 9.0 17.0 - 18.0 ≤0.75 ≤0.5  0.040 0.25-0.33
Typical analysis in %
23-10-2012 – REV00
Avenue Paul Girod
73403 UGINE Cedex - France
www.ugitech.com
2
Although Ugitech takes special care to check the accuracy of the information printed here, it cannot guarantee that this information is accurate, reliable, comprehensive and reproductible as such on its
customers' premises. Ugitech disclaims all responsibility for the use of the data indicated above and invites you to contact its Technical Assistance Department for a specific study of your needs.
Magnetic
properties
Non-magnetic in annealed condition.
Slight magnetism produced by cold-finishing operations.
Corrosion
resistance Environment Behaviour
Nitric acid Good
Phosphoric acid Average
Sulphuric acid Average
Acetic acid Average
Sodium carbonate Average
NaCl (Salt spray ASTM B117 Ra<0.5 µm) Average (300 to 700 h)
Humidity Good
Sea water Restricted use
UGIMA
®
4305 has good corrosion resistance in many environments.
Its corrosion resistance is typical of an austenitic steel and is similar to that of a standard 4305 in every
respect.
 The use of UGIMA® 4305 is compatible with all the fluids, lubricants, oils and greases used in the
machining industry.
 However, UGIMA® 4305 is not recommended for use in marine environments and highly oxidising
chemical environments.
 In addition, as with all "resulphurised" steels, special care must be taken when using UGIMA® 4305
in acid or chloride environments that are liable to pitting or crevice corrosion: component geometries
allowing the formation of areas where corrosive products might collect and corrode will therefore be
avoided.
 Optimum corrosion resistance is obtained where a surface is free from all traces of machining oil or
foreign particles (iron, for example).
UGIMA
®
4305 is pickled in the same way as 304 grade steel.
Decontamination of steels with a high sulphur content is not recommended owing to the complexity and cost
of this operation; however, if it is necessary, the recommended decontamination / passivation process is as
follows:
1 volume 52% nitric acid
1 volume water
ambient temperature
short duration
wash carefully when the process is completed
 The corrosion resistance of a stainless steel depends on many factors related to the composition of
the corrosive atmosphere (chloride concentration, presence or absence of oxidizing agents,
temperature, pH, agitation or no agitation, etc.), as well as to the material (surfaces free from iron
particles, surface finish such as hardening, polishing, and so on). Experimental precautionary
measures should also be taken for certain tests, such as the salt spray test (ASTM B117 standard):
for example marking labels that might cause corrosion run-outs and reduce the test resistance time
should not be used on the sample.
Machinability The machining performance of UGIMA
®
4305 is very good, due to the specific optimisation of the
inclusion population.
Productivity gains of 25% to 45% over the standard 4305 have been obtained with UGIMA
®
4305
depending on the cutting operations. The difference from a standard 4305 will be all the more
marked due to the high cutting conditions.
This grade can therefore be used to best advantage on high-performance machines providing
high cutting conditions (high rotational speeds and spindle power) and with coated carbide cutting
tools rather than high-speed steel tools that do not withstand a high temperature rise.
Thanks to controlled inclusion population (in particular that of UGIMA
®
oxides), the same cutting
conditions have resulted not only in less tool wear than that observed with a standard 4305 but

3. UGIMA®
4305 - UGIMA®
303
Chemical analysis
C Si Mn Ni Cr Cu Mo P S
≤0.07 ≤0.75 1.5-2 8.0 – 9.0 17.0 - 18.0 ≤0.75 ≤0.5  0.040 0.25-0.33
Typical analysis in %
23-10-2012 – REV00
Avenue Paul Girod
73403 UGINE Cedex - France
www.ugitech.com
3
Although Ugitech takes special care to check the accuracy of the information printed here, it cannot guarantee that this information is accurate, reliable, comprehensive and reproductible as such on its
customers' premises. Ugitech disclaims all responsibility for the use of the data indicated above and invites you to contact its Technical Assistance Department for a specific study of your needs.
also improved chip breakability which, in some extreme cases, can prove useful for preventing
chip entanglement problems.
Finally, the surface finishes of the machined parts are noticeably better with UGIMA
®
4305 than
with a standard 4305.
If you want to make the most of the grade's potential for your components and working
environment, contact our Technical Advisers.
Welding UGIMA
®
4305 can be welded by all types of arc processes (MIG, TIG with or without filler metal,
coated electrodes, submerged arc welding, etc.), resistance (spot or seam), friction, electron
beam or LASER welding.
However, during arc welding, welding energies should be limited to reduce the risks of thermal
cracking in the weld metal zone (WZ) and heat-affected zone (HAZ), which are inherent in
austenitic stainless steel containing a high percentage of sulphur. If filler metal is used, grade
ER308L (Si) filler is suitable. To limit the risks of thermal cracking in the weld metal zone, filler
grade ER312 may be preferred.
In MIG welding, the Ar- (+ possibly He-) based shielding gas will have to contain 2 to 3% CO2 or
O2 to make it easier to stabilise the welding arc; in TIG welding, the filler gas will be pure Ar (+
possibly He). H2 and N2 can be added to the shielding gas if required.
In LASER and electron beam welding, the risk of thermal cracking will be even greater. In these
cases, cooling stress liable to cause cracking should, as far as possible, be minimised by
choosing geometries that reduce stress concentration and by appropriately adjusting welding
parameters (usually increasing linear welding energy to reduce stress during cooling).
Heat
treatment
The annealing treatment that gives UGIMA
®
4305 its lowest mechanical properties involves
heating to 1050 - 1100°C for approximately 15 minutes, followed by rapid air or water cooling. In
this case, the properties obtained are:
Rm 500 - 750 Mpa
Rp 0.2 200/500 Mpa
A% 50-70
Forging
UGIMA
®
4305 should not be forged. However, if this operation is required, the material should be
heated to 1180 - 1250°C and the work should be finished at a temperature higher than 950°C.
Products
available
Product Shape Finishing Tolerance
Bars rolled 13
Bars descaled 13
Cold-finished drawn, turned, ground bars 6 to 11
Hexagonal cold-finished bars 11
Others: contact us.