Does ASTM A123 apply to bolts and fasteners as a galvanizing specification?
ASTM A123 does not cover threaded bolts and fasteners. ASTM A153 and F2329 are the ASTM specifications that cover the requirements for hot-dip zinc coating of fasteners.
ASTM A123
This specification covers the requirements for hot-dip galvanizing on iron and steel products made from rolled pressed and forged shapes, castings, plates, bars, and strips. It does not cover threaded fasteners that are centrifuged or otherwise handled to remove excess zinc.
ASTM A153
This ASTM specification covers zinc coatings applied by the hot-dip process on iron and steel hardware. This specification is intended to be applied to hardware items that are centrifuged or otherwise handled to remove excess zinc. A153 is applicable to steel hardware items of Classes A, B, C, and D.
- Class A – Castings – Malleable Iron, Steel
- Class B – Rolled, pressed, and forged articles
- Class C – Fasteners over 3/8” diameter and washers 3/16” and ¼” thick
- Class D – Fasteners 3/8” diameter and smaller, rivets, nails and washers under 3/16” thick
Since threaded fasteners are spun at high speeds in a centrifuge to remove excess zinc from the threads, they would fall under the A153 class C specification.
ASTM F2329
The standard specification that covers the requirements for hot-dip zinc coating applied to carbon steel and alloy steel bolts, screws, washers, nuts, and special threaded fasteners applied by the hot-dip coating process. Nails and rivets are not included in F2329. It is intended to be applicable to fasteners that are centrifuged or otherwise handled to remove excess zinc.
ASTM F2329 vs. ASTM A153
A153 covers galvanizing on many products including fasteners, while F2329 is specific to threaded fasteners, nuts and washers. The two specifications have virtually identical coating thickness requirements. Also, A153 and F2329 have different sampling requirements; F2329 requires more samples per lot than A153. Portland Bolt can meet the requirements for both F2329 and A153 Class C. Portland Bolt performs hot dip galvanizing of threaded fasteners within our 137,0000 square foot manufacturing facility. Contact us if you have a need for hot-dip galvanized fasteners or with any technical questions regarding hot-dip galvanizing. One of our experienced sales reps will be happy to answer any of your questions.
can we use this for BS products?
@Manoj- We are not familiar with the requirements of the British Standards, so we are unable to answer this question. Apologies.
It seems that there is not any real difference bitween A153 & A123
@Sadjad- The key difference is that A153 parts are handled in such a way as to remove excess zinc like spinning. A123 is not. The rest of the process is quite similar.
I have one question for valuable advice.from appearance, how to differentiate the memeber is galvanized by ASTM A123 or ASTM A153, for instance, contractor claim that anchor bolt belong to thread hardware, and it is galvanized as per ASTM A153 with lower thickness compared with ASTM A123.In front of such case, how to testify it??
@Lei- If the bolt had threads, and was handled in such a way to remove the excess zinc (like spinning), then A153 is the correct standard to follow. There are small portable devices available that can measure the zinc thickness if there is concern.
Can you extend a RoHS certificate at this HDG process?
@Luis- we are able to certify that the items we manufacture and galvanize in our facility will meet the RoHS requirements. For items that are manufactured by others, it would be on a case by case basis.
Greetings,
Thank you for the useful content. I am having difficulty determining the hot dip zinc coating needed for an anchor bolt 60M(60mm) and 1.75 m in length, as well as the galvanizing coat for its respective hex fasteners. Also a high tension rod( U Bolt) 14mm diameter and 2 meters in length also with its respective fasteners. Any insights would be deeply appreciated. Many thanks
Sal from Dubai
@Sal- Are you asking which galvanizing standard you should be using? The only ones we are familiar with are ASTM A153 and F2329, both of which are the same process. We are are not certain what standards are commonly used in Dubai, so we cannot speak to those.