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Swedish standard SA 2.5, SA 3 for sand blasting for cast iron part
Q. I need to know the technical details about the following- Surface preparation - Cast Iron part (gratings, used for cooking ranges); the surface needs to be prepared by sand blasting as per Swedish Standard, SA 2.5 minimum or better as per Swedish Standard, SA 3. If it is possible then please inform about the surface finish value ( Ra, Rmax eg.) which can be achieved by the above mentioned process.
Please respond as early as possible.
Best Regards,
Souren Palsteel company - Ahmedabad, Gujarat, India
Q. Dear Mr. Souren Pal,
I am also interested in the relationship between the SA standards SA 1, 2 21/2 and 3 and Ra. An interesting answer on your question which may be of help to me?
Best Regards,
Laure Spriensma- Jirnsum, The Netherlands
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Q. I WOULD LIKE TO INQUIRE INFORMATION REGARDING SAND BLASTING PROCEDURES, EQUIPMENTS AND MATERIAL, AS DESCRIBED IN SWEDISH STANDARD SA1, 2, 2.5, 3? YOUR COOPERATION ON THIS MATTER WILL BE HIGHLY APPRECIATED. FADI MUSALLAM- ABU DHABI, UAE
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Q. May I know the surface profile difference between SA 2.5 and SA 3 in microns?
Shahaji Doltade- UAE
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Q. Please give me the details of S.A. 2.5. Where can we purchase this standard?
Kuldeep Bhatemployee - India
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Ed. note: Please see Ted Mooney's entry of June 4, 2010 for purchasing information.
November 1, 2008A. I hope this will clear your queries on Blasting and surface preparation..
BLAST CLEANING - PREPARATION GUIDES>
grade - BS 7079 SS 05 59 00
description, when viewed with the naked eye
- SA 2
- thorough blast cleaning:Commercial finish 65% clean
The surface shall be free from visible oil, dirt and grease, from poorly adhering mill scale, rust, paint coatings and foreign matter. Any residual contamination should be firmly adhering.
- SA 2.5
- very thorough blast cleaning: Near white metal 85% clean
The surface shall be free from visible oil, dirt and grease, from poorly adhering mill scale, rust, paint coatings and foreign matter. The metal has a greyish colour. Any traces of contamination shall be visible only as slight stains in the form of spots or stripes.
- SA 3
- blast cleaning to pure metal: White metal 100% clean
The surface shall be free from visible oil, dirt and grease, from poorly adhering mill scale, rust, paint coatings and foreign matter. The blasted surface must have a uniform metallic colour.
BLASTING GRADES
Following is a table giving a clear indication of the comparative blasting grades applicable to national and international standards:
BLASTING GRADE COMMON STANDARDS COMPARISON
SSPC steel structures painting council
BS 7079 British standards
SS 05 59 00 Swedish standards
BS 4232
NACE, National Association of Corrosion Engineers
white metal (SP5) SA 3
1st quality
grade 1
near white metal (SP10) SA 2.5
2nd quality
grade 2
commercial finish (SP6) SA 2
3rd quality
grade 3
Sanjay Mungee
- RUST GRADES
- A Surface mostly covered with adherent mill scale, with little or no rust
B Mill scale has begun to flake, rust has started to form
C Mill scale has rusted away or can be scraped off easily and slight pitting has taken place
D Mill scale has rusted away and general pitting can be seen with naked eye
- Baroda, Gujarat, India
^-- this reader rates this thread:
June 11, 2009
dear sir
we want photographs of standard blasting like as sa 2, sa 2.5, sa 3 etc.
regards
coatings - Vadodara, Gujarat, India
August 13, 2009
I want sand blasting profile books for SA2 and 2 1/2.and also colour catalog (IS code , BS code , RAL Code). with complete pictures. please let me know where can I find this.
Thanking you in advance.
contractor - Vizag, AP, India
August 26, 2009
Q. I want to know the term "Sa" in blasting standard is stand for what?
my boss always ask me and I cannot answer.
help me please...
Painting Executive - Johor, Malaysia
September 3, 2009A. Hi, Ahmad. This is a Swedish Institute for Standards designation, as previously described,but I don't know if "Sa" is an abbreviation or acronym in Swedish or just an arbitrary pair of letters where "S" stands for "surface" :-)
Regards,
Ted Mooney, P.E.
finishing.com
Brick, New Jersey
September 5, 2009A. SA stands for Standard Abrasive..Similarly ST means Standard Tooling
Rahul T.
- Mumbai, India
October 28, 2009A. Sa Simply stands for Sand as that is the abrasive medium that they used to determine the blasting standards on the 4 Rust Grades for ISO 8501-1 [link is to spec at TechStreet].
Lee Wilson
Remember Sand was the most widely used abrasive back in the days before the health risks of silicosis were identified.
Alternatively St stands for Steel sorry its nothing more technical but that's it guys and the reason I know is that I asked SIS years ago when I first started Inspection to settle an ongoing debate between myself and a colleague.
The relationship between the standards Sa3 and 2.5 is practically identical except that a 2.5 allows for staining or traces of contamination i.e. Very thorough blast cleaning. When viewed without magnification, the surface shall be free from visible oil, grease and dirt, and from mill scale, rust, paint coatings and foreign matter. Any remaining traces of contamination shall show only as slight stains in the form of spots or stripes.
An Sa3 does not have any visual contamination present it is a white metal finish.
for a more definitive view at amounts of contamination which are allowed visually to be included in a blast please take a look at the joint Nace SSPC blasting standards which are equivalents however not identical to the ISO 8501-1 standards these standards give a better representation of the actual amounts of contamination which should be present.
Nace 1, SP5, Sa 3 = 0%
Nace 2, SP10, Sa2.5 = 5% Staining
Nace 3, SP6, Sa2 = 33% Staining
Nace 4, SP10, Sa1 = 100% as long as its tightly adherent
Lee Wilson
Nace Level 3 Coating Inspector
Nace CIP Instructor & Lecturer
Icorr Level 3 Painting Inspector
inspection services - United Kingdom
February 5, 2010
Thanks a lot everyone. It was really helpful.
Priya Suryakant- Bangalore,Karnataka, India
March 19, 2010
Q. Dear sir,
I want to know about measuring instrument for surface finish SA 2.5. I also want to know about from which size of grit we can achieve surface finish SA 2.5.
Your sincerely
student - ROHINI, DELHI, INDIA
March 19, 2010A. Hi, Prashant. The above discussion leads me to believe that Sa2.5 is not a "surface finish" but a visual standard for cleanliness and is not related specifically to grit size and surface roughness standards like Ra / Rz and cannot be measured with a profilometer. Do you have a copy of Sa2.5 handy? Thanks.
Regards,
Ted Mooney, P.E.
finishing.com
Brick, New Jersey
April 9, 2010
Q. Kindly furnish details of surface preparation SA 2.5 required our customer for Sg Iron casting, Can we done by mechanical grinding or some other process.
ARUN KUMAR KATHARE- Shahabad, Karnataka, India
April 9, 2010A. Hi, Arun. There is a pretty good synopsis of Sa 2.5 requirements further up the page. But it is a copyrighted specification, and you would need to obtain a copy of it to see its text.
Regards,
Ted Mooney, P.E.
finishing.com
Brick, New Jersey
P.S.: Please see my entry of June 4,2010 for information about where/how you can order the standard.
May 5, 2010
Thanks for the information that SA 2.5 is not measurable in Ra, but we have seen specifications, such as in containers manufacturing that surface finish to SA 2.5 to achieve 25 to 30 micron finish. Is it correct!
S P S DHINGRA- Kolkata, India
May 5, 2010Hi, S P S. Hopefully someone who is more knowledgeable about this will answer, because I have already done my best.
But I can't see how you can measure things that are covered by Sa 2.5, like discoloration, visible oil, and greyness with a profilometer.
Nor can I see how you can reasonably expect a given surface profile from performing operations that comply with a blast cleaning specification that is unconcerned about surface profile, and which apparently permits the use of any blasting material of any size for any amount of time.
Regards,
Ted Mooney, P.E.
finishing.com
Brick, New Jersey
June 4, 2010
Dear Sir,
I want to know about the detail of SA 2.5 about blasting for steel equipment.
Regards,
K.Shanthi
project engineer - Chennai,Tamil Nadu, India
June 4, 2010 A. Hi, Shanthi. The general meaning of Sa 2.5 is explained above.
My understanding is that the full details are covered by specification SS 55900, available from the Swedish Standards Institute at www.sis.se -- but that this standard was actually canceled in 2001 and is now superseded by ISO 8501-1 [link is to spec at TechStreet].
Good luck.
Regards,
Ted Mooney, P.E.
finishing.com
Brick, New Jersey
June 9, 2010A. The blasting standards as depicted in ISO8501-1 are visual standards for surface cleanliness
Lee Wilson
Once a substrate is abrasive blasted the blast achieved is then compared to the visual reference pictures which are contained within ISO8501-1 and a comparison made between the blasting standard achieved and the standard required.
When you speak of Ra you are speaking of surface profile, roughness or anchor pattern which is the peak to trough amplitude of the blast profile usually expressed and specified in microns and created during the blasting process this is usually measured with surface replica tape, surface comparators or surface profile needle gauges however surface profile is not an indication of the surface cleanliness do not get confused surface profile and surface cleanliness as depicted in ISO8501-1 are separate requirements.
I hope that this helps
Best Regards
Lee Wilson
NACE 3
NACE Instructor
ICorr Level 3
inspection services - United Kingdom
January 17, 2011
Q. I would like to know reference/guidance for the relation between cleanliness standard with steel structural condition/type.
e.g :
SA-2.5 is applied for structure on what condition? or
what grade suitable with what condition of structure?
structure engineer - Jakarta, Indonesia
May 5, 2011
Q. Sir
can we use silica sand following sa 2.5 & sa 3 if not which kind of sand we use.
employee - Rahim Yar Khan, Pakistan
May 11, 2011
Sa.2.5 is precisely is expected for existing structure, while Sa.2 is for new installation.
Joseph Okoye- Ikoyi, Lagos, Nigeria
August 21, 2011
Q. Which term to follow regarding surface preparation of storage tanks, whether surface cleanliness or surface profile or both because both seems two different requirement of surface preparation for applying coating on metal surface.
A. Aziz- Karachi, Pakistan
October 1, 2011A. It seems there is a whole book to be written on the blasting standard requirements, the differences between the required grades and surface profiles.
Hans vd Linde
In short, our company approach the problem as follows:
The client needs to decide (or be advised depending on the aplication) what type of coating will be applied to the steel, this will decide the required blasting grade as specified by the coatings manufacturer (the norm seems to be SA2.5).The coatings manufacturer will also specify the required DFT (Dry Film Thickness) of the required coating to be applied.The DFT requirement is what needs to be looked at when one decides the roughness of a surface profile in microns.
- Alberton, Gauteng, South Africa
October 26, 2011
Q. Please advise me how to inspect sand blasting for steel structures like I beam, channel, plate.
1. What the pressure should I maintain to get the fine surface preparation.
2. What microns should be there after sand blasting.
quality control - Saudi Arabia
^- Privately contact this inquirer -^
October 26, 2011
Hi, Mohamed.
That's an awfully broad question, cousin -- especially in view of all that preceded it. What blasting standard are you trying to comply with?
Regards,
Ted Mooney, P.E.
finishing.com
Brick, New Jersey
October 28, 2011
Q. I have a similar question to the one asked on October 26. For us we are being asked to prepare metal surfaces by Sandblasting to a Sp-10 level finish. What does that entail and how do we inspect for this?
Carlos Montanezmanufacturing - Stockton, California
December 31, 2011 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread
Q. Is it possible to achieve surface roughness 6.3 Ra from initial surface roughness 12.5 Ra after grit blasting with SA1 or SA1-1/2? Material forged steel.
Abdullah Ansariwind energy - Pune, Maharashtra, India
January 19, 2012A. Are you sure you are talking Ra? I don't think you can achieve those results using any blasting media
AF Kenton
Huntingdon Valley, Pennsylvania
February 1, 2012Q. For example: machined surface roughness Ra 12, can we blast it to SA 2.1/2 and achieve surface roughness Ra6.3?
Abdullah Ansari
wind energy - Pune, Maharashtra, India
February 2, 2012
A. Hi, Abdulah. I think AF (Tony) said no.
To the best of my knowledge, blasting is for cleaning (removing surface contaminants). I personally have never heard of anyone attempting to polish an article by blasting.
Regards,
Ted Mooney, P.E.
finishing.com
Brick, New Jersey
January 25, 2012
Q. What is the size and specification of SA2.5 iron grit?
Ashok Kumar- India