Eugene
12-30-2006, 11:10 AM
http://www.cartech.com/epg_rathbone/images/rathbone_new2.jpg
Jim mentioned that the Red One might have a lens mount partially composed of Invar.
I found some info about Invar that is made by Carpenter Tech.
http://www.cartech.com/
Will the Red One have any ceramic parts?
http://www.hightempmetals.com is the website that I got the info from.
High Temp Metals, Inc.
12910 San Fernando Rd.
Sylmar, CA 91342-3601
mailto:sales@hightempmetals.com
Invar 36
"Drilling
When drilling a 3/16" diameter hole, a speed of about 40/FPM could possibly be used, and the feed should be about .002" to .0025" per revolution, for a 1/2" hole, approximately the same speed could be used with a feed of about .004" to .005" per revolution. The drills should be as short as possible, and it is desirable to make a thin web at the point by conventional methods. By conventional methods, we mean do not notch or make a crank shaft grinding. It is suggested that heavy web type drills with nitrided or electrolyzed surfaces be used. The hole, of course, should be cleaned frequently in order to remove the chips, which will gall, and also for cooling. The drill should be ground to an included point angle of 118° to 120°
Reaming
Reaming speeds should be haft the drill speed, but the feed should be about three times the drill speed. It is suggested that the margin on the land should be about .005" to .010", and that the chamfer should be .005" to .010" and the chamfer angle about 30°. The tools should be as short as possible, and have a slight face rake of about 5° to 8°.
Tapping
In tapping, a tap drill slightly larger than the standard drill recommended for conventional threads should be used, because the metal will probably flow into the cut. It is suggested that on automatic machines, a two or three fluted tapping tool should be used. For taps below 3/16", the two fluted would be best. Grind the face hook angle to 8° to 10°, and the tap should have a .003" to .005" chamfered edge. If possible, if binding occurs in the hole in tapping, the width of the land may be too great, and it is suggested that the width of the heel be ground down. Again, it is suggested that nitrided or electrolyzed tools be used. Speed should be about 20/FPM."
Super Invar 32-5
"Machinability
Super Invar 32-5 machines similar to, but not as well as , Type 316 austenitic stainless steel. Its machinability rating is approximately 25% that of AISI B1112. This alloy is somewhat difficult to machine because the machined chips are gummy and stringy. Work hardened bars can result in some improvement in machinability.
Tool geometries normally used for austenitic stainless steels are suitable for this alloy. All tools should be kept sharp with a fine finish, be as large as possible, and rigidly supported.
Recommended cutting fluids are 1 to 1 blend of sulfachlorinated petrolum oil containing 8 to 10% fatty oil and a paraffin blending oil, or a water emulsifiable cutting fluid with polar and extreme pressure additives.
Parts should be degreased and cleaned as soon after machining as possible to remove any residual sulfur which can cause grain boundary embrittlement.
When using carbide tools, surface speed feet/minute can be increased between 2 to 3 times over the high speed suggestions. Feeds can be increased between 50 to 100%.
On certain work, the nature of the part may require adjustment of speeds and feeds. Each job has to be developed for best production results with opitmum tool life. Speeds and feeds should be increased or decreased in small steps."
"Heat Treating for Lowest Thermal Expansion and Optimum Stability
The recommended heat treating pracitce for lowest thermal expansion and optimum stability is to heat at 1550°F for 1 hour, water quench, followed by a stress relieving operation at 600°F for 1 hour, air cool and age at 200°F for 24 hours, then air cool.
Because this alloy oxidizes readily at heat treating temperatures above about 1000°F, it is recommended parts be heat treated in a protective environment such as vacuum, hydrogen, dissociated ammonia, or inert gases."
For lots more info on Invar, look at the link below. Invar 36 is good enough.
http://www.americanmachinist.com/304/Issue/Article/False/9152/Issue
Jim mentioned that the Red One might have a lens mount partially composed of Invar.
I found some info about Invar that is made by Carpenter Tech.
http://www.cartech.com/
Will the Red One have any ceramic parts?
http://www.hightempmetals.com is the website that I got the info from.
High Temp Metals, Inc.
12910 San Fernando Rd.
Sylmar, CA 91342-3601
mailto:sales@hightempmetals.com
Invar 36
"Drilling
When drilling a 3/16" diameter hole, a speed of about 40/FPM could possibly be used, and the feed should be about .002" to .0025" per revolution, for a 1/2" hole, approximately the same speed could be used with a feed of about .004" to .005" per revolution. The drills should be as short as possible, and it is desirable to make a thin web at the point by conventional methods. By conventional methods, we mean do not notch or make a crank shaft grinding. It is suggested that heavy web type drills with nitrided or electrolyzed surfaces be used. The hole, of course, should be cleaned frequently in order to remove the chips, which will gall, and also for cooling. The drill should be ground to an included point angle of 118° to 120°
Reaming
Reaming speeds should be haft the drill speed, but the feed should be about three times the drill speed. It is suggested that the margin on the land should be about .005" to .010", and that the chamfer should be .005" to .010" and the chamfer angle about 30°. The tools should be as short as possible, and have a slight face rake of about 5° to 8°.
Tapping
In tapping, a tap drill slightly larger than the standard drill recommended for conventional threads should be used, because the metal will probably flow into the cut. It is suggested that on automatic machines, a two or three fluted tapping tool should be used. For taps below 3/16", the two fluted would be best. Grind the face hook angle to 8° to 10°, and the tap should have a .003" to .005" chamfered edge. If possible, if binding occurs in the hole in tapping, the width of the land may be too great, and it is suggested that the width of the heel be ground down. Again, it is suggested that nitrided or electrolyzed tools be used. Speed should be about 20/FPM."
Super Invar 32-5
"Machinability
Super Invar 32-5 machines similar to, but not as well as , Type 316 austenitic stainless steel. Its machinability rating is approximately 25% that of AISI B1112. This alloy is somewhat difficult to machine because the machined chips are gummy and stringy. Work hardened bars can result in some improvement in machinability.
Tool geometries normally used for austenitic stainless steels are suitable for this alloy. All tools should be kept sharp with a fine finish, be as large as possible, and rigidly supported.
Recommended cutting fluids are 1 to 1 blend of sulfachlorinated petrolum oil containing 8 to 10% fatty oil and a paraffin blending oil, or a water emulsifiable cutting fluid with polar and extreme pressure additives.
Parts should be degreased and cleaned as soon after machining as possible to remove any residual sulfur which can cause grain boundary embrittlement.
When using carbide tools, surface speed feet/minute can be increased between 2 to 3 times over the high speed suggestions. Feeds can be increased between 50 to 100%.
On certain work, the nature of the part may require adjustment of speeds and feeds. Each job has to be developed for best production results with opitmum tool life. Speeds and feeds should be increased or decreased in small steps."
"Heat Treating for Lowest Thermal Expansion and Optimum Stability
The recommended heat treating pracitce for lowest thermal expansion and optimum stability is to heat at 1550°F for 1 hour, water quench, followed by a stress relieving operation at 600°F for 1 hour, air cool and age at 200°F for 24 hours, then air cool.
Because this alloy oxidizes readily at heat treating temperatures above about 1000°F, it is recommended parts be heat treated in a protective environment such as vacuum, hydrogen, dissociated ammonia, or inert gases."
For lots more info on Invar, look at the link below. Invar 36 is good enough.
http://www.americanmachinist.com/304/Issue/Article/False/9152/Issue