Can blind holes be threaded?

Yes. Blind tapped holes are commonly used for concealed fasteners. Bottoming taps are ideal for maximizing thread engagement without break-through.

How deep should a blind hole be?

Typically 3–4× the hole diameter. For threaded blind holes, allow additional unthreaded space at the base.

What’s the tolerance range?

±0.05 mm for diameter and ±0.1 mm for depth is common in CNC precision machining.

What do buyers need to provide when requesting a quote?

Buyers should provide hole diameter, total depth, thread specs, CAD files (2D and STEP), material type, and quantity forecast.

Can bronze rust in coastal environments?

Bronze does not rust like iron, but marine air can accelerate patina formation due to increased moisture and salt exposure.

What causes bronze to turn green?

The green coloration on bronze comes from copper reacting with air, moisture, and carbon dioxide to form copper carbonate, also known as patina.

Is patina a sign of damage?

No. Patina is a natural and often protective layer that forms on bronze, helping shield the underlying material from further corrosion.

How can I keep bronze looking new?

To maintain a clean finish, apply wax or lacquer coatings regularly, avoid acidic or abrasive cleaners, and store or install bronze in dry, well-ventilated environments.

Is bronze or stainless steel better for outdoor fixtures?

Both are durable, but bronze offers an aging aesthetic with protective patina, while stainless steel provides a more consistent, modern appearance. The choice depends on visual goals and environmental exposure.

Can I request bronze parts with pre-applied patina or protective finishes?

Yes. YISHANG offers customizable bronze finishes, including pre-patinated and coated options based on client specifications.

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Custom Steel Metal Tube Sheet Metal Fabrication Welding Laser Cutting Service

Item Name	Custom Steel Metal Tube Sheet Metal Fabrication Welding Laser Cutting Service
Technology	Laser cutting, CNC lathing, welding, grinding.
Dimensions	Produced according to your drawings.
Material	Can be SPCC, stainless steel or aluminum.
Color	Common is white, black, grey. Can be customzied.
Surface Treatment	Powder coating for SPCC.
Features	High precision, tolerance is only 0.1 mm.
Sample	Welcome to customize metal products and metal parts samples to inspect the quality.
Services	Professional custom metal processing service.

From yesterday’s picture, you can see that we use a laser cutting machine to position and cut square edges and circular holes on the metal square tube.

Ensure that the openings on each square tube are correct and the cuts are complete without burrs.

Cutting circular holes of different sizes on different surfaces of square metal pipes is a very difficult task.
Our laser cutting engineers design different cutting locators through drawings, which can fix the material in the correct position, and the position of each hole produced by the laser meets the customer’s requirements.