Thanks Thanks:  0
Likes Likes:  0
Needs Pictures Needs Pictures:  0
Picture(s) thanks Picture(s) thanks:  0
Results 1 to 14 of 14
  1. #1
    Join Date
    Apr 2005
    Location
    Brisbane
    Posts
    8

    Default Thread on stainless steel square bar

    Hi,

    I am hoping to use a square stainless steel square bar as a balustrade. The ends of the square bar will protrude through a 75mm square wood post. In order to fasten the horizontal bars I need to thread the end of the bars so that I can put a nut on and pull them tight.

    I am using 6.35mm (1/4") square stainless steel square bar grade T304 or T316. I am hoping to get about 50mm of thread machined onto the ends. I was hoping to do a DIY job by grinding the corners off the bar to make it mostly round and then to purchase a dye to put a thread on the end. I have 28 bars that I need to put ends on. I am trying to determine if I can get away with a M8 bolt which I believe has a 6.8mm root diameter. The diagonal length of the square bar is 8.98mm so I expect to grind off the four corners until the diagonal is 8mm and then add the thread. As the bar is only 6.35mm across the middle there will be a short flat spot on the threads on each of the four sides. I do not expect that this will be a problem as there will not be a huge load on the bars. The other option is to grind the square end to a 6mm round and tap a M6 thread on the end.
    I am concerned that the dye may not last for the 28 ends that I need to do. I do not have access to a lathe. Other options include welding a short piece of threaded rod onto the end of the bar.

    Any comments on the practicality of this or other suggestions will be appreciated.

    Sean

  2. # ADS
    Google Adsense Advertisement
    Join Date
    Always
    Location
    Advertising world
    Posts
    Many





     
  3. #2
    Join Date
    May 2003
    Location
    Kuranda, paradise, North Qld
    Age
    62
    Posts
    5,639

    Default

    Sean,
    I've never tried tapping SS but I can't imagine it would be easy, especially if it's not really round. Could you drill into the post at 90deg to the SS bar and have a hole through the bar at the intersection. Drive a screw into the post so it passes through the SS bar and bites into the other side. This might look a bit neater too.

    Mick
    "If you need a machine today and don't buy it,

    tomorrow you will have paid for it and not have it."

    - Henry Ford 1938

  4. #3
    Join Date
    May 2005
    Location
    Newcastle
    Age
    72
    Posts
    3,363

    Default

    your post suggests that there is no problem in SS welding
    If so then cut you problems in half by welding a good flat washer to one end of the square section then you will only have to worry about thread on the other end


    The other thought maybe to pull the posts together with a long clamp mark the square section stainless drill through holes at each end say 5 mm and insert pins then release the clamp might even look good

    Rgds
    Ashore




    The trouble with life is there's no background music.

  5. #4
    Join Date
    May 2006
    Location
    WA
    Posts
    8

    Default S/S bars

    [quote=SBartleet]Hi,

    I am hoping to use a square stainless steel square bar as a balustrade. The ends of the square bar will protrude through a 75mm square wood post. In order to fasten the horizontal bars I need to thread the end of the bars so that I can put a nut on and pull them tight.

    I am using 6.35mm (1/4") square stainless steel square bar grade T304 or T316. I am hoping to get about 50mm of thread machined onto the ends. I was hoping to do a DIY job by grinding the corners off the bar to make it mostly round and then to purchase a dye to put a thread on the end. I have 28 bars that I need to put ends on. I am trying to determine if I can get away with a M8 bolt which I believe has a 6.8mm root diameter. The diagonal length of the square bar is 8.98mm so I expect to grind off the four corners until the diagonal is 8mm and then add the thread. As the bar is only 6.35mm across the middle there will be a short flat spot on the threads on each of the four sides. I do not expect that this will be a problem as there will not be a huge load on the bars. The other option is to grind the square end to a 6mm round and tap a M6 thread on the end.
    I am concerned that the dye may not last for the 28 ends that I need to do. I do not have access to a lathe. Other options include welding a short piece of threaded rod onto the end of the bar.

    Any comments on the practicality of this or other suggestions will be appreciated.

    Sean
    []

    Sean,
    If you buy S/S studs or bolts with nuts and have a welding machine, your job will be easier and cut in half the time or even less (its my opinion taking in consideration that you have 56 ends to thread) if you take the last option presented by you.

    2.5mm 304/8 S/S electrodes for AC (240V machines) can be purchase in small quantities and 70 to 90 amps.
    Distortion, can be controlled by depositing a little weld at oposite sides into a pre made 45 degrees bevel at the end of the bar or bolt/stud. Ensure no grease or oil is present in the weld joint. It will make holes in the weld and therefore the weld becomes weaker.

    Ensure that the weld joint will stay inside the 75mm square post. You do the sums.

    Just a reminder for you. When you tighten the nuts to tense the bar, be aware that you will be pulling the posts in if they are not held in position.

    Cheers
    Ariel

  6. #5
    Join Date
    May 2006
    Location
    WA
    Posts
    8

    Default

    [quote=ariel]
    Quote Originally Posted by SBartleet
    Hi,

    I am hoping to use a square stainless steel square bar as a balustrade. The ends of the square bar will protrude through a 75mm square wood post. In order to fasten the horizontal bars I need to thread the end of the bars so that I can put a nut on and pull them tight.

    I am using 6.35mm (1/4") square stainless steel square bar grade T304 or T316. I am hoping to get about 50mm of thread machined onto the ends. I was hoping to do a DIY job by grinding the corners off the bar to make it mostly round and then to purchase a dye to put a thread on the end. I have 28 bars that I need to put ends on. I am trying to determine if I can get away with a M8 bolt which I believe has a 6.8mm root diameter. The diagonal length of the square bar is 8.98mm so I expect to grind off the four corners until the diagonal is 8mm and then add the thread. As the bar is only 6.35mm across the middle there will be a short flat spot on the threads on each of the four sides. I do not expect that this will be a problem as there will not be a huge load on the bars. The other option is to grind the square end to a 6mm round and tap a M6 thread on the end.
    I am concerned that the dye may not last for the 28 ends that I need to do. I do not have access to a lathe. Other options include welding a short piece of threaded rod onto the end of the bar.

    Any comments on the practicality of this or other suggestions will be appreciated.

    Sean
    []

    Sean,
    If you buy S/S studs or bolts with nuts and have a welding machine, your job will be easier and cut in half the time or even less (its my opinion taking in consideration that you have 56 ends to thread) if you take the last option presented by you.

    2.5mm 304/8 S/S electrodes for AC (240V machines) can be purchase in small quantities and 70 to 90 amps.
    Distortion, can be controlled by depositing a little weld at oposite sides into a pre made 45 degrees bevel at the end of the bar or bolt/stud. Ensure no grease or oil is present in the weld joint. It will make holes in the weld and therefore the weld becomes weaker.

    Ensure that the weld joint will stay inside the 75mm square post. You do the sums.

    Just a reminder for you. When you tighten the nuts to tense the bar, be aware that you will be pulling the posts in if they are not held in position.

    Cheers
    Ariel

    Sean,

    I forgot to say that Ashore has a good idea as is welding the bolts/studs.
    You decide.

    But be aware that discolouration of the S/S will take place with welding, unless you passivate the area or use a S/S wire wheel or a S/S wire brush to polish the area.

    Cheers

    Ariel
    ___________________________________________________

    KNOWLEDGE DOES NOT TAKE PLACE, ONLY MAKES ONE WISER

  7. #6
    Join Date
    May 2006
    Location
    WA
    Posts
    8

    Unhappy Reply

    Quote Originally Posted by SBartleet
    Hi,

    I am hoping to use a square stainless steel square bar as a balustrade. The ends of the square bar will protrude through a 75mm square wood post. In order to fasten the horizontal bars I need to thread the end of the bars so that I can put a nut on and pull them tight.

    I am using 6.35mm (1/4") square stainless steel square bar grade T304 or T316. I am hoping to get about 50mm of thread machined onto the ends. I was hoping to do a DIY job by grinding the corners off the bar to make it mostly round and then to purchase a dye to put a thread on the end. I have 28 bars that I need to put ends on. I am trying to determine if I can get away with a M8 bolt which I believe has a 6.8mm root diameter. The diagonal length of the square bar is 8.98mm so I expect to grind off the four corners until the diagonal is 8mm and then add the thread. As the bar is only 6.35mm across the middle there will be a short flat spot on the threads on each of the four sides. I do not expect that this will be a problem as there will not be a huge load on the bars. The other option is to grind the square end to a 6mm round and tap a M6 thread on the end.
    I am concerned that the dye may not last for the 28 ends that I need to do. I do not have access to a lathe. Other options include welding a short piece of threaded rod onto the end of the bar.

    Any comments on the practicality of this or other suggestions will be appreciated.

    Sean
    I sent you a replyto help you out but can not see it in your thread.

    Ariel

  8. #7
    Join Date
    Sep 2003
    Posts
    165

    Default

    If you decide to use a Die on the bar, i'd make sure you buy a HSS Die rather than the usual Chrome Tungsten Alloy ones as it will last a lot longer, and i'd use liberal amounts of cutting fluid or Trefolex, and when you grind the corners off a lil, i'd be very carefull not to get very much heat into it at all, is it is likely to get harder as it is heated (depending on the grade).
    It's Ripping Time!!!

  9. #8
    Join Date
    Oct 2007
    Location
    Redcliffe
    Posts
    4

    Default

    I've worked a lot in S/S and I would shy away from trying to thread it. Is it possible to drill the ends and attach a small turnbuckle or weld one on. They look OK and if you are using solid bar you wont be putting too much tension on as the post will give first. Pickling paste will remove any discolouring but wear gloves and glasses. You can get it from BOC.

  10. #9
    Join Date
    Oct 2007
    Location
    Alexandra Vic
    Age
    69
    Posts
    2,810

    Default

    1. 304 is a general grade material and not suited to exposed use, will 'tea stain' within weeks if exposed to weather or pollutants.

    2. It is prone to hard spots that will stuff the faces on a drill even when being drilled with correct speeds, feeds and lubes. It is virtually impossible to use where production internal threads are required, as it is near imposible to drill the correct base hole and then tap it. Have not tried to cut an external thread with a die, but would not anticipate being successfull. Free machining grades are available (308?) but as expensive as 316.

    3. Die will have 3 or 4 interupted cutting faces and rounded corner square will also have 4 interuptions per revolution. Dies are intended for threading continuous round material that is accurately presized, and do not like interupted cuts. I suspect that a die would be lucky to cut a single thread before chipping or breaking. Winding a chipped or broken die of a part formed thread will damage the thread anyway.

    4. 1/4 sq material is very flimsy and would struggle to support its own weight if tensioned horizontally between uprights. While it might provide a cosmetic barrier, it is most unlikely to provide a safety barrier, which is the primary purpose of a balustrade.

  11. #10
    Join Date
    Jan 2004
    Location
    Mackay Qld
    Posts
    3,466

    Default Get it done quickly

    Hi SBartleet
    If you have access to a welder should not be an issue.Welders can hired very reasonably and if you can't weld yourself there must be some one who can weld in your circle of friends and acquaintances. Failing that one of the mob from the Brisbane contingent may put their hand up to help. Stainless electrodes are much easier to start and use than the regular ones.

    The easiest solution in terms of time effort and money spent has got to be the welding.

    56 ends of 50mm will run out around 2.8 meters of rolled thread or 3pieces if they still sell them in 1 meter cut lengths.

    2.5 mm 316L Stainless steel electrodes might be had From a sheet metal works or a small engineering shop or maybe even a welding shop catering to DIY the Brisbane boys can advise on that one maybe )

    You will need :

    • A hacksaw
    • A file
    • A welder and helmet & gloves
    • A bit of a knock up jig to align said sq bar and the thread
    • 3 x 1 meters of 6mm 316 roll thread and nuts.
    • 12 to 15 of 2.5mm 316L Stainless electrodes
    • Mate to weld with them
    • Two or three hours of time


    Leave a gap of 1mm for tacking.

    Go on then !No excuses, get into it!
    Grahame

  12. #11
    Join Date
    Jun 2006
    Location
    East Warburton, Vic
    Age
    54
    Posts
    14,138

    Default

    Guys, take note of the date . Think the job has probably been finished by now
    Cheers

    DJ


    ADMIN

  13. #12
    Join Date
    Nov 2006
    Location
    Heidelberg, Victoria
    Age
    79
    Posts
    2,251

    Default

    A last thought,

    If your balustrade consists of a substantial top rail, and end posts, and you wish to fill in the height with a some form of safety barrier, consider using stranded 3mm s/s cable with turnbuckles at each end. The ends of each cable are turned back on themselves, then crimped, to form a loop.

    Each turnbuckle is attached to the post, then connected to the ends of the cables. A bit of tightening, and wallah, jobs done. This is the architects delight, trust me.

    Ken

  14. #13
    Join Date
    Jan 2006
    Location
    Blue Mountains NSW Australia
    Posts
    592

    Default

    Guys, take note of the date . Think the job has probably been finished by now
    Well I don't know that I agree.

    I was going through the "to do" list on the weekend, and I have two or three jobs not done from 1998.

  15. #14
    Join Date
    Mar 2005
    Location
    Hobart
    Posts
    71

    Default

    Quote Originally Posted by charter View Post
    Pickling paste will remove any discolouring but wear gloves and glasses. You can get it from BOC.
    Safety note re pickling paste.

    The pickling pastes I am familar with contain hydrofluoric acid. This is probably one of the most dangerous acids to deal with as it migrates into your bones and attacks bone strength.

    Can't emphasis enough the need for protective clothing

    John

Similar Threads

  1. stainless steel wire balustrade in wooden Posts
    By soey22 in forum FLOORING, DECKING, STUMPS, etc.
    Replies: 7
    Last Post: 21st March 2008, 04:01 PM
  2. Stainless Steel welding
    By Clinton1 in forum WELDING
    Replies: 15
    Last Post: 6th April 2007, 01:58 AM
  3. Stainless Steel Sandpaper
    By Sculptured Box in forum FINISHING
    Replies: 3
    Last Post: 22nd January 2006, 09:28 PM
  4. Stainless Steel Butt hinges
    By martrix in forum Links to: TIMBER & HARDWARE SUPPPLIERS
    Replies: 1
    Last Post: 9th December 2005, 11:27 AM
  5. Stainless steel splashback
    By Para in forum KITCHENS
    Replies: 20
    Last Post: 25th November 2004, 01:50 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •