[ianrelon]

hi im very new in welding and DIY only.
Just like to know what is hit and miss
like 100 hit 300 miss

thanks

[Otto Nobedder]

I have absolutely no idea what that means.

Context, please?

[Otto Nobedder]

I've never heard "hit and miss" used in welding terminology.

[weldin mike 27]

Hey,
the actual terminology may be a local term, but judging by the Hit miss 100 300 it sort of sounds like weld 100 miss 300. in a stitched weld. Be careful however, in many welds like this the "miss" measurment is a pitch measure. This means its the centrepoint of the welds. Measure 300mm put a mark and then the weld is 100mm stradling with 50mm on each side of the mark. This means the gap between welds is only 200 mm. Phew. I hope this doesnt confuse you.

Mick

[Otto Nobedder]

Ahh,

Thanks, Mick, That makes sense!

I didn't read it as a weld schedule.

I'd guess it translates to 10 CM of weld, 30 CM skipped?

[ianrelon]

this is quoted in my engineering plan drawing done by architectural draftsmen
coz im doing pergola in my backyard and this required for building permit

says in the plan section of bims and purlins is welded 100 hit & 300 miss
and i dont know about this

[ianrelon]

thanks weldin mike
thats a very big help
cheers mate

[weldin mike 27]

Hey,

All sweet guys,

Just remember the bit about the pitch, measured just like a row of holes. Measursed between centres rather than the gap.
Most stitch welds in Australia are measured this way but I cannot vouch for tje rest of the world.

Ps The weird terminolgy probably stems from the fact that its an Architectural drawing. Those blokes just make stuff up and then expect us to figure it out.

Mick

[Otto Nobedder]

Good point. Here in the US, a spec of "3 on 9" would mean 3" of weld, 6" of space, because the "on 9" would refer to centers.

[Otto Nobedder]

Under that premise, "100 hit, 300 miss" would mean 10 Cm of weld and 20 Cm of space.

Best be sure what is meant.

[weldin mike 27]

Hey ,

Its always good ammo to win a fight with, because some people would swear that it sould be 100 weld 300 gap when it is as you say, 100 weld 200 gap. But i dont get payed to figure out indistinguishable symbols / drawings. Put down the torch and call in inspector or engineer. Not that I couldnt but its not for me to work out.

Mick

[TamJeff]

this is quoted in my engineering plan drawing done by architectural draftsmen

Now this statement could branch off in many directions. That translates into "engineers", or from my experience. . ."Imagineers."

Not meaning to derail the thread and this is mostly being said tongue-in-cheek, but whenever I see architects mentioned. . .my blood suddenly runs cold. . .and then real hot shortly thereafter.

[delraydella]

According to the 29th edition of Machinery's Handbook,(page 1476) Length is the length of the weld and Pitch is the center to center spacing of the welds.

[weldin mike 27]

Hey,

That's right Jeff, theyre all like " i drew it in pencil so you should be able to make it out of metal........ .........What?" Lol There is an Engineer in my town who does his drawings, to the letter of the law, accounting for all the nessesary forces, weights and what not but does not put a single weld spec on them. Useless.

Mick

[ianrelon]

thanks to all of you guys
thats right 100mm is the weld and 300mm is the gap

according to the drawing this is 2 purlins 50mmx100size joint to each other

cheers to everyone nice one to discuss and additional to my knowledge as DIYer

[Otto Nobedder]

So you found the "miss" is the gap between the welds, if I understand correctly.

So the equivalent weld/pitch spec I'm used to seeing would actually be 10 cm on 40 cm, meaning 10 cm welds, with 30 cm spaces so the welds are 40 cm on-center.

I'll have to file this one away in case I encounter.

Thanks,

Steve S

[ianrelon]

thats right 100mm weld and 300mm is the gap

this discussion is very helpful
here in Australia the surveyor and city council engineer are very strict, i must to follow what is the instruction in my sketch plan
otherwise im going to take down everything if didnt follow
thats why this question come out 100 weld and 300 miss and im looking for the right and accurate answer

and im going to right down this in my log book for future reference

thanks to all of you

[Alexa]

Ianrelson.

Quote:
"... A staggered weld is simply designed as a fillet weld with a hit and miss so you would call it as 6" on 6" off or as required for the particular fillet weld. so the weld would then be half as strong as the same size continuous weld. ..."

Source: http://www.eng-tips.com/viewthread.cfm?qid=300697
Post: 13 Jun 11 11:45 by poster csd72

Alexa

[ianrelon]

big tango alexa
that is additional knowledge