A grade 8 is primarlily a metric grade 8.8 bolt to a DIN standard and is
widely used in structural connections here in Europe. You may be able to get
the correct information from Borstlap who are a very large Dutch bolt and
nut company. They have several depots in the USA. Contact them via
> -----Original Message-----
> From: Neil Glaser [SMTP:NGlaser(--nospam--at)pkainc.com]
> Sent: Monday, February 28, 2000 12:54 PM
> To: seaint(--nospam--at)seaint.org
> Subject: Re: Grade 8 Bolts
> This definitely sounds like a fatigue problem and if it is, it will likely
> occur again. Grade 8 bolts are roughly the equivalent of A490 bolts,
> they are not typically used for structural applications. If it is a
> problem, I would assume that the bolts are located within the column
> Due to the beam rotation this would cause large stress fluctuations in the
> since the beam will rotate about the column flanges. Short of some type of
> modification to move the bolts outside the column flanges, your best
> would be to recommend frequent inspections and replacement of the bolts.
> Neil J. Glaser, P.E.
> Fountain Conner wrote:
> > I have an long-time industrial client who recently replaced a bunch of
> > *missing* structural bolts with "Grade 8" (I assume SAE, Grade 8) bolts.
> > can only guess what happened to the original bolts. I'm sure they
> > stolen, so that leaves the options of working loose or breaking under
> > repetitive load cycles -- This is a vertical bolt, attaching a crane
> > to a column cap plate. Can anyone say, "fatigue"?
> > I'm not comfortable with this replacement. So far as I can tell, the
> > 8 machine bolt is hard, tough, and *brittle*. 'Sounds like courting
> > disaster to me...
> > I recommended replacing the *new* bolts with A325, but the client is
> > reluctant to spend money twice for the same work.
> > Guidance and counsel, anyone?
> > Fountain E. Conner, P.E.
> > Gulf Breeze, Fl. 32561