Machining 304 SS on Davenport Machines

[dugudugu]

Does anyone have experience machining threads in 304 stainless steel materials on a Davenport Screw Machine or any high speed production type equipment (similar to a davenport)? Need some help with speeds and feeds.

Dugu

 

[BobUXL]

Dugu,
Machining threads on a Davenport (I am assuming a Model B)can be done by roll threading or chasing. Speeds and feeds can depend on the type of stainless you are using. For example, speeds for 304 will be slower than 304L. Using a Ugima 304/304L from Ugine Stainless and Alloys, Inc. in the US, will allow speeds at much higher rates. For example, we specify speeds of 30-60 SFPM. Be careful where you get your stainless. The machining performance will vary greatly. Look at the better mills. The price is somewhat higher, but so is performance and support.

Take a look at

http://www.uginestainless.com,

in the products section. Click on the 304 data sheet. There will be a machining chart for your reference.

 

[TVP]

Carpenter is another one of the "better mills" that BobUXL was mentioning. Their Project 70+® version of 304 will perform similarly to Ugima from Ugine, which is to say, substantially better than standard 304. You can obtain more information from their website:

http://www.cartech.com/machining_zone/index.html

 

[BobUXL]

TVP,

The Ugine Ugima alloys are very different that the domestic stainless alloys. The domestic alloys just use sulfur, and in some cases a chemistry modification, to enhance machinability. The Ugima alloys uses a controlled oxide (a complex oxide formed during processing), in addition to sulfur, that becomes soft and lubricious at cutting temperatures above 800C. This controlled oxide is unique to Ugine's Ugima alloys and are not present in the domestic alloys. Since the MnS sulfide inclusions loses its lubricity above 800C, machinability decreases. The oxide will melt, coat the tool and reduce the friction between the chip and tool. Therefore, the Ugima stainless alloys have the ability to machine at much faster rates. For example, I have run our Ugima 304/304L on a Tornos Deco 2000 Swiss on a single point cutting operation at 950 SFPM, 0.007 ipr, 0.040 DOC, and run out of machine speed. We advertize machining speeds our Ugima 303 XL of 1200-1600 SFPM on CNC machines using carbide tools. Our machining data is included in our data sheets on our website -

http://www.uginestainless.com

 

[dugudugu]

Thanks for all the input.

Dugu