How To Make Hairpin Legs In A Modern Factory (A Step By Step Guide)
Today I am going to show you EXACTLY how to make hairpin legs in a modern factory.
In fact, this is the same process that helped us make amazing hairpin legs for our clients from worldwide countries(such as UK,Canada, USA,Australia, New Zealand and etc..) in the past years.
But I should point out something out:
This is an uncovered guide to make hairpin legs in a factory.
So if you are interested in crafting custom metal hairpin legs (like us), you’ll love the simple steps in this guide.
Let’s get started.
First of all, you will have to prepare the raw material which include raw steel and steel plates.
The best quality steel for hairpin legs is cold rolled steel, which has smooth surface. The lower quality iron seems rough and rusty on the surface. In the meantime, the better quality material cost more as well.
And the diameter of the round steel rod can affect the hold weight of the legs. The larger size of the rod diameter, the stronger the hairpin legs will be. There are usually 2 size options for rod diameter in the round steel material market: 10mm and 12 mm.
Like the following material is cold rolled steel in our warehouse. We put it on the dry shelives to avoid them going rusty.
If your table is heavy and you would like to be solid, we recommend you use the thicker steel rod (12 mm in diameter). Like the one below.
Cut The Cold Rolled Steel To Length
As we know, the raw steel is too long for us to make the hairpin legs into the size like 4 inches or 28 inches, etc.. In this case, we will have to calulate the steel length that each hairpin leg cost at first and then use the electric hacksaw to cut them into a specific length.
For example, if you would like to make 2 rod 8 inches steel hairpin legs with an angle of 45 degrees, the steel will have to cut into 51 centimeters each.
Please note that you should count in the length in the bending corner.
We cut the steel through electric jigsaw.
Cut The Base Plate To Shape
The base plate material is long, the standard thickness is 3 mm. And you will have to cut them into small pieces as the mounting plate of hairpin legs.
Most mounting plate on hairpin legs are L-shaped.
In our factory, we usually make the mounting plate with these 2 specifications:
- 110 mm x 110 mm x 3 mm
- 120 mm x 120 mm x 3mm
For example, we marked the size of the base plate on 14 inches 2 rod hairpin legs in the picture below:
Compared to DIY hairpin legs by tools and hands,we use cutting machine to cut the steel plate and it works accurately and saves us a lot of time. Here is our cutting machine:
Once you have finished cutting the steel plate. You are going to drill out holes on the small steel plate.
To insert the screws in that used to attach the top, such as table, sofa, bench, stool, etc. , you will have to drill holes on the mounting plate.
In our factory, we drill countersink holes for countersink screws for further use.
Before drilling holes, you’ll have to adjust the drilling machine to ensure the holes were drilled in the right position.
To ensure firm attachment, we usually drill 4 or 5 holes on the mounting plate, 2 drilled on the either end of the “L” and 2 or 3 drilled on either side of the angle
People usually use the M4 countersink screws to attach the hairpin legs to tops. So you should use the M4 driller.
In our years of experience, double welded base plates are more sturdy and stable for the moving and shifting furniture. To improve our quality and make it perfect, we use angle iron to make an assembly fixure. And weld a verticle angle brackelte piece to it.
After you have prepared the mounting plate, you are going to bend the steel rod.
Since you have already prepared the straight steel rod from cutting process in step 1, now you will use the fabricator to bend the steel rod.
In general, legs are initially made from a length of steel rod that is twice the desired finished height. For example, a 14 inch hairpin leg originally made from a 28 inch steel rod.
Adjust the strength of the fabricator according to the angle of the steel rod. The larger strength, the larger bend angle.
Set the fabricator to ensure the bend corner is in the center of each steel rod and make the hairpin as equal as possible.
Once you have prepared the hairpin, you’ll go to the most interesting part:
Heat the steel rod bend corner to make it sturdy and avoid breaking when using. And it also helps the hairpin legs form into shape natrually.
To ensure the legs bending uniformity, please heat the same area of each rod, each time and bend the rod to the same degree.
Once you have get the perfect hairpin rod, set the fabricator in that work status and then repeat the bending process for numerous time. And you will get all the hairpin legs in the same specificaion.
When it comes to welding, safty is the most important part for you.
Since welding on zinc produces poisonous gas (the corner brace is often galvanized) , we recommend you use extra care equipment in a ventilated area.
Here’s the 2-step process for welding:
Firstly,set the corner brace into fixure and clamp it on the welding working desk. Put the hairpin on the corner brace and lean it against either end of the mounting plate.
Secondly, tack the weld against the ends of the hairpin. Double check the hairpin are in the right position as you want.
Welding is a fantastic scene, and it is the most important step for the quality of the hairpin legs.
After welding, you’ll polish the hairpin legs to get ready for painting.
To remove the rust and the thin rust-resisitant coating on the raw steel hairpin, you’ll remove need to remove.
But how to remove the coating?
Please ONLY polish the thin anti-rust coating otherwise you will distroy the hairpin legs. So keep the distance between the polisher and the hairpin legs.
Once it looks smooth and new on the surface, you have finished the polishing. This video show you the more clear scene:
The welding trace on the base plate will also disappear after polishing.
You’ll paint another new layer on the hairpin legs through spraying in the next step.
Through spraying the hairpin legs, you’ll get amazing colors, such as white, yellow, black, green, red, etc (The regular hairpin leg color is black).
Spraying make the hairpin legs living and it matches different customer’s appetite. And it is the best painting method to produce the colorful hairpin legs in bulk.
Below are the painted hairpin legs after spraying in our factory.
To spray the hairpin legs, you’ll go through the following steps:
First, clean the hairpin legs after polishing. The best way to clean the hairpin legs is to use a little bit of degreaser to get off the rust resistant coating, such as acetone, dishwashing pad.
Second, spray the paint evenly on the cleaned hairpin legs. You should set a proper spray speed and spray volume according to the hairpin legs quantity. Make sure you have spray all over the hairpin legs.
You will spray about 3 coats in this process, which includes:
- Primer coat
- Rustoleum lacquer
- Color powder coat
For primer coat, we recommend you use acid primer. It makes sure your paint stick to the steel rod and steel plate and prevent the paint chipping off over time.
Rustoleum lacquer is good for the metallic finish.
For the color coat, you just change a new spray can and spray the color as your customer required.
Third, keep the painted hairpin legs in the ventilational area. The hairpin legs get dry quickly in the well ventilated area and away from heating or hot place to avoid the coating chipping off.
After you finished painting the legs, leave the hairpin legs in the well ventilated area for 24-48 hours.
If you done all the steps in the right way, you’ll test the hairpin legs quality in the following step below.
When it comes to quality control, you should pay attention to to the following points:
- Ensure the hairpin leg bend radius is even
- Ensure the 4 legs in a set are in the same height
- Ensure the vertical steel rod on the center of the bend corner for 3 rod hairpin legs
- Ensure the steel rods was welded
- Ensure the painting coat is fine
The best part?
Let’s go through each point one by one.
With an even leg radius, the hairpin leg will be stable. And the same leg radius of each hairpin leg can ensure they are on the same height in a set.
In the below picture, you can see the difference:
You can use the bender from the bending machine to check the leg radius.
To check if the 4 hairpin legs are on the same height, you just put them together on a flat desk and put a ruler on plate on them, then the difference is clearly as below:
From the above picture, you can see the 4 legs are not in the same height, that means it table will not stable if you attached these hairpin legs with them.
So this is an important step for quality control.
Another quality control point is special for 3 rod hairpin legs.
3 rod hairpin legs are actually made from 2 steel rods, 1 long steel rod bended into a 2 rod hairpin leg and then wild the 3rd steel rod on the bend corner. But the quality problem often happens: the 3rd steel rod was not in the middle of the bend corner.
The left one is perfect in the below picture while the steel rod of the right one goes to the left.
In this case, the 3 rd steel rod was welded on the wrong position.
Next, you should check all the welding positions to check if you have any non-welding points.
And you also should see around if the paint coat was chipped off or not.
Until now you have finished quality control and you can parepare to pack the good quality hairpin legs.
To wrap the hairpin legs, we recommend you use thick foam (at least 0.7 mm) to wrap and wrap at least 2 layers with foam.
And to prevent the hairpin legs from rattling around, we recommend you add a wrap of tape in the middle as follows:
Our stand package for hairpin legs is 1 piece per bag and 4 pieces per carton box.
I’d like to mention that you should follow your customer’s packing requirement and that’s why we would not pack in a standard way since we provide custom hairpin legs service to our customers and all our solutions are exclusive.
After packing, here you go to the last step:
The hairpin leg floor protector is a small part that prevent the hairpin legs from scratching when moving the furniture here and there.
It is very useful even it is a very small rubber. So we recommend you tell your customers to order the rubber floor protectors when they puchase hairpin legs.
The screws are also an extra accessory for hairpin legs. You will have to use the right screws that fit the holes on the hairpin legs.
So you do not miss the screws when you order hairpin legs and if you have all the accessories in a set, your clients will get better customer experience.
Now I’d Like To Hear From You
There you have it:
My 9-step technique guide to make metal hairpin legs.
Now I’d like to hear from you…
Which technique from today’s post are you ready to learn first? Welding or spraying?
Are you going to make a quality control list and check the quality of your hairpin legs order before shipping?
Either way, let me know by leaving a comment below right now.