What is Cold Roll-Formed Parts Workmanship?

Conformance to specification.

Absence of injurious defects.

Absence of attributes not specifically described in purchase document.

Production by means designated, intended or implied.

That should do it.

milo

Hot-Rolled and Cold-Rolled of Formed Parts. In pressure vessels industry (e.g.) we use dished heads which are formed from steel plates. Sometimes we specify those heads to be "hot rolled" or "cold rolled", which indicating its formation either in the presence of heating or not. In which in "cold rolled" we have to calculate the extreme fiber elongation to be within certain limits, otherwise a heat treatment is required.

Cold roll forming is simply the material being shaped between two rollers. These rollers are not unlike the old "ringer" washing machines where one's clothes were pressed between the rollers in order to squeeze the excess water from them.

The workmanship part comes in to play as follows:

1) There should be no tell-tale 'roller-marks' ( officially called tool marks ), scratches, or smears on the finished piece of work. Smears occur when the rollers "skid" on the material instead of feeding it through.

2) The finished piece should show no appreciable distortion allong its edges. Distortion will occur if the clearance between the rollers is too 'tight'. Distortion can be prevented by multiple passes through the rollers with more clearance during the first pass and less clearance applied with each subseqent pass.

Basically, your finished part should be free from any surface anomallies, be "square" and/or consistant in thickness, curvature, width, etc.

I've been in the Quality Control (inspection) business for 35 years and the items I've mentioned above, if not complied with, will surely rate your finished part(s) as having "Poor Workmanship". I hope this helps.

QMAN

thanks - all your comments are making sense and helpful!

with definition pasted here;

my 2nd question is: "workmanship" is customer defined (ie: customer voice) or is internal defined and/or driven? how to avoid conflicts? since if it is internal driven then tighter workman requirements will likely causing maybe unnecessary delay for parts delivery.

A. Definition of Workmanship:

- noun

1. The art or skill of a workman or workwoman.

2. The quality or mode of execution, as of a thing made.

3. The product or result of labor and skill; work executed.

(above cited from Dictionary.com)

- noun

1. Skill in an occupation or trade.

(above cited from WordNet)

work·man·ship (wûrkmn-shp)

n.

1. The skill of a craftsperson or artisan.

2. The quality of something made, as by an artisan: a silver tray of excellent workmanship.

3. Something made or produced by a workman.

4. The product of effort or endeavor.

www.thefreedictionary.com/

B. Definition of Rollforming:

Is a continuous bending operation in which a long strip of metal (typically coiled steel) is gradually formed in tandem sets of rollers dies until the desired cross-sectional profile is obtained. Rollforming is ideal for producing parts with long lengths & in large quantities.

Wikipedia, the free encyclopedia - Cite This Source

THE Customer is the final Judge. If he rejects, he will not pay. Your process has to be aligned to meetinhg the customers spoken and unspoken requirements.

WOrkmanlike does have root in Workman.

However, if the workman fails to perform satisfactorily, he is not paid.

Thus the Customer is the defining authority.

How to avoid conflicts? Understand the requirements. Do not agree to requirements that you dod not understand or cannot deliver.

Tighter internal requirements do not mean delay, they may mean insurance that what you provide will be acceptable.

I would urge you to think in a spirit of generosity toward Delighting the customer, rather than thinking in a more stingy fashion to begrudge the customer what they are due.

In all relationships the customer is goilden, because he has the gold...

milo "underpromise and overdeliver"

I totally agree "the Customer is the defining authority." however, in reality is: "defining authority" is normally NOT doing that defining job part for "workmanship".

So thta make the "workmanship criteria" difficult to be documented, stated and communicated to WORKMAN.

If internal define it, who would has most authority to do so - too tight, then no body buy-in; while defined too loose, later customer may deem that is non-issue - "you guys have got wrong focus/wasting time"

Think above this: if workmanship is defined and set-up internally and go by: one "gold-holder" may like it while another think you waste time - never appreciated it, but you have product produced from same rollforming process...

Like an easy question but not easy anwser for application...as all would agree I believe "workmanship" is something to do with quality - however, as someone sayied: quality has three levels and 8 or 16 dimensions...puzzle remains unsolved..

Actually the "puzzle" won't remain unsolved for long. Either your process meets customer s acceptance criteria and your company makes money, or Your process fails to meet customer expectation and your company goes broke.

Don't make it too complicated. I have successfully managed quality technology and laboratory function in manufacturing and steelmaking for many years. Over million tons of steel, Unknown how many parts for automobiles, trucks, CAT Tractors...planes motorcycles, appliances, you name it.

Either you meet the customer requirements or you don't.

milo

You are ablolute RIGHT! it take not long before I come up with the followings. All-in-all, workmanship defined has to be from customer.

The cold-rollformed part workmanship is its totality of fulfilling and/or meeting its Work Order (stated & implied) requirements. More specifically, meeting following four (4) criteria without jeopardize human health & safety, damage to machine/tooling.

1. Parts be within Controlled Drawing specified dimensional tolerances

2. Part surfaces have no visual gouges, scratches, dents, cracks, etc.

3. Part conforms to requirement per WO's Special Instructions, if any. (Item usually not included attribute requirement on Controlled Drawing )

4. Absence of injurious defects, such as excessive burrs; toxic and/or foreign substance.

this way, I made workmanship definition a dynamic one (PDCA) - PLEASE COMMENT!

These are really only three, and I would put in the following order:

1. Parts be within Controlled Drawing specified dimensional tolerances and requirements (such as mechanical properties)

2. Part conforms to requirement per WO's Special Instructions, if any.

3. Absence of injurious defects, such as visible gouges, scratches, dents, cracks, excessive burrs, toxic and/or foreign substances.

my take. I changed visual to visible.

milo

milo, you are GURU! I love it!

thank you very much!

Let us know how it goes.

milo