What are the different types of machined holes?
Recessed top – A common feature of machined holes is to recess the top of the hole into the workpiece. This is typically done to accommodate the head of a fastener and allow it to sit flush with the workpiece surface. Two types of recessed holes are a counterbore, which has a cylindrical recess, and a countersink, which has a cone-shaped recess.
What should the inner bend radius of sheet metal be?
When the radius is less than recommended, this can cause material flow problems in soft material and fracturing in hard material. Localised necking or fracture may also occur in such cases. It is recommended that minimum inner bend radius should be at least 1 times material thickness.
Why is my bobbin thread running out of thread?
• Improper bobbin thread tension – too tight or too loose • Bobbin thread run-out o Inconsistent yardage from bobbin to bobbin • Bobbin over-spin o Causing a short tail that cannot be picked up by the needle thread during the beginning of the next stitching cycle Solutions: • Use a quality bobbin thread.
What is the distance between two bolt holes?
2. Gauge Distance (g):It is the distance between the two consecutive bolts of adjacent rows and is measured at right angles to the direction of load. 3. Edge Distance (e):It is the distance of bolt hole from the adjacent edge of the plate. Bolted Connections 9 where g ml = partial safety factor at ultimate stress = 1.25 f u
What happens when a hole is too close to a bend?
If a hole is drilled or CNC punched too close to a bend in a sheet metal component it can take on a tear drop or “pulled” form. In Figure 1 below you can see a hole that has been pulled by the action of the bend that is too near to it.
Can you thread a hole in a button without a needle?
You need to be able to thread the hole in your button without a needle – as if you were stringing beads. Cut a length of thread or floss, about 12″ long. Thread one end through the hole in the button.
Which is the incomplete thread on a screw?
Vanish thread is also known as partial thread, washout thread, or thread runout. Incomplete lead thread is the incomplete thread at the starting end of a screw thread. Incomplete runout thread is the incomplete thread at the terminating end of a screw thread. Right-hand and Left-hand Threads
Which is part of a thread is not fully formed?
Vanish thread is that portion of the incomplete thread that is not fully formed at the root or at crest and root. It is produced by the chamfer at the starting end of the thread forming tool. Vanish thread is also known as partial thread, washout thread, or thread runout.