Here in the UK I was taught that a machine screw is threaded all the way to the head whereas a bolt has an unthreaded portion so that there is no threaded part wiithin the material been held together by the bolt. OTOH I have heard such bolts referred to as "Fitted bolts" On 7 March 2016 at 17:48, Neil wrote: > My general knowledge has been that once the diameter gets to 1/4", then > they're called bolts, and then they're usually hex head. Yes there are > exceptions. Taught to me by a machinist some years ago. However, I also > call a 10-32 screw a screw, because the local hardware store (Home > Depot) calls them that. > > For full context on this situation, the purchase list included "10-32 x > 1" pan-head screws ". The teacher said that she had no idea what I > wanted, so bought #10 screws (sheet metal), and 10-32 "bolts", and said > that I was not specific. Saying no prob, that I just needed the 10-32 > (screws) that she got, she argued that I should've said "bolts", and > those are not screws. Even after showing her that the package actually > said "machine screws", she demanded that they're bolts. I could not > bother to get into it beyond that. > > I suspect we're no longer on PIC topic tag anymore though. > > > > On 3/7/2016 12:16 PM, Sean Breheny wrote: > > > https://en.wikipedia.org/wiki/Screw#Differentiation_between_bolt_and_scre= w > > > > In the US anyway, the core distinction is traditionally whether the > > fastener _needs_ a nut and is held still during tightening (bolt) or is > > intended to screw into threads in the materials being joined (either wi= th > > pre-cut threads or by thread-forming) (screw). Some things are clearly > > bolts (carriage bolts since they cannot be screwed into a threaded hole > due > > to their lack of a driving feature and their square feature on the shaf= t > > near the head). Some things are clearly screws (like wood screws or > > self-tapping sheet metal screws). Other things are not so clear (like > > typical pan-head machine screws which may also use nuts) > > > > > > On Mon, Mar 7, 2016 at 10:56 AM, wrote: > > > >>> Maybe this is regional. I grew up in a junk yard. We had machine > screws, > >> not > >>> to be confused with wood screws, and bolts. Bolts were big. Machine > >> screws > >>> were small. > >> My understanding of the difference is that screws need a screwdriver, > flat > >> blade or cross blade (Pozi-drive etc.). > >> > >> Bolts require a spanner as they have a hex head, or require an Allen k= ey > >> or similar tool, as they have a socket head, or don't have a means of > >> driving, but require a nut on the other end, e.g. coach bolts. > >> > >> -- > >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > >> View/change your membership options at > >> http://mailman.mit.edu/mailman/listinfo/piclist > >> > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 __________________________________________ David C Brown 43 Bings Road Whaley Bridge High Peak Phone: 01663 733236 Derbyshire eMail: dcb.home@gmail.com SK23 7ND web: www.bings-knowle.co.uk/dcb *Sent from my etch-a-sketch* --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .