ASTM FAQs
Non-Standard Thread on Structural Bolts
Is it possible to manufacture an A325 or A490 structural bolt with a non-standard thread length?Yes. At Portland Bolt we are frequently asked this question. In order to better understand the answer, some background information on these two specifications is necessary. Both the A325 and the A490 specifications cover high strength, heavy hex, structural bolts from ½” diameter through 1½” in diameter. Both ASTM A325 and A490 specify shorter thread... Read more
ASTM and SAE Differences
What are the main difference between ASTM 307 GR.B, ASTM A449, and SAE Grade 5 bolts?There are two specifying bodies when it comes to fasteners. ASTM (American Society for Testing and Materials) covers primarily bolts and fasteners for construction applications. SAE (Society of Automotive Engineers) covers fasteners for automotive, machinery, and OEM applications. ASTM A307 grade B is made from a low carbon steel and is a relatively low strength... Read more
ASTM A325 vs A449
I have two items that use 1" bolts, one is ASTM A325 and the other is ASTM A449, I would like to just use one. Which is the one that meets or exceeds the other?These bolts are identical with regard to strength and chemistry. There are very minor differences in the hardness requirements, but the proof load, tensile, and yield strength requirements are the same. From a manufacturing standpoint, we make these bolts using the same raw material and the same heat treating and production methods. Our strength by... Read more
Grade 55 Steel Properties
Can I use ASTM 108 Round Bar, a CF-1018 round bar, for F1554 Grade 55?The problem with ASTM A108, 1018CF is that there are no mechanical requirements and typically the test reports that accompany this steel reflect the chemistry only and not the strength of the steel. Test reports will need to accompany this material that reflect all four of the values listed below, and these values will need... Read more
Grade C Eliminated From ASTM A307
What happened to ASTM A307 Grade C?One change with regard to specifications that will have a significant impact on the construction fastener industry is the August 2007 elimination of the grade C designation within the ASTM A307 specification. ASTM A307 is the standard specification for low carbon steel construction fasteners. Until recently, A307 had three grades A, B, and C. Grade... Read more
SAE Grade 8 vs ASTM A490
What are the differences in strength and application between SAE Grade 8 and ASTM A-490?In some respects SAE J429 grade 8 bolts and ASTM A490 bolts are similar, and in other respects they are different. The first thing to address is the fact that these specifications are covered by different organizations. SAE (Society of Automotive Engineers) covers bolts for automotive, equipment, and OEM applications, whereas ASTM (American Society for... Read more
ASTM Letter Designations
What do the letters at the beginning of an ASTM standard signify?Every ASTM standard is identified by a unique designation. It includes a capital letter (A – G), followed by a serial number ranging from one to four digits, a dash, and finally the year of issue. For example, a common bolt specification is A449 – 07a, although when specified the standard’s year designation is usually... Read more
ASTM Tie Rod Standards
Is it appropriate to spec ASTM F1554 in place of A36 tie rods for higher strength applications? What are the lengths these rods come in, the availability of each grade, and cost differences?Most ASTM standards address the recommended application of the fastener. There are often two or three different ASTM specifications with similar chemical and mechanical properties, but with differing applications. ASTM F1554 is a specification that is designed for anchor bolts embedded in concrete. Since your application is for tie rod assemblies, it would appear that... Read more
ASTM A193-B7 Thread Pitch
What bolts are available in ASTM A193-B7 and what is the appropriate thread pitch to specify?“My plant uses hex head cap screws, ASTM A193-B7 as standard. We typically stock the constant thread series 8 TPI fasteners above 1 inch diameter. However, many tapped items like expansion joints come with UNC thread counts, like 7 threads per inch (TPI) for 1-1/4″ diameter bolts. This causes a problem sometimes when fasteners don’t... Read more
ASTM A36 vs A307
What are the differences between A36 and A307?ASTM A36 is a steel (raw material) specification, while ASTM A307 is a fastener specification. In other words, once you take A36 round bar and cut it, thread it, bend it, forge a head on it, or otherwise process it and turn it into a fastener, it becomes an A307 bolt. Often times, ASTM A307... Read more