1) All procedures for component replacement should be followed. This includes any
   patterns specified for tightening screws.

2) If an adjustable torque wrench is available, the build spec should be used. 

   From an engineering standpoint, it is important that the screws be tightened
   with some confidence to the actual torque, and that the final torque be
   consistent.  It is recommended that the service technicians have an
   adjustable torque driver, not a fixed tool. All the tolerances for the 
   system are specified to be within the accuracy of a reasonably high-quality 
   adjustable tools (+/- .5 in-lb up to 10 in-lb), and is what we have been using in the
   lab throughout development. It should be noted that the steel-to-steel spec for
   an M5 screw (centerplane) is __33.3__ in/lbs. 

   **However, a preset tool can be used provided the service engineer 
     adheres to the caveats below .**

3) These specs will be included in the next rev of the manual; engineering will be 
   updating there drawings per the changes noted below. Manufacturing should start
   using these new specs after the release of the new drawings.

4) This took a lot of time to compile - please read it completely. (How's that for
   begging people to read a manual ;-)



			______________	_______________	  ______________  ____________________
			Orig. BSD Spec	Sun Spec	  Adj. BSD Spec	  Use of 6.0 in/lbs OK
			for Mfg. Build			  for Mfg. Build  In the Field
			______________	_______________	  ______________  ____________________

Guidelines:
  torque range
  relative to spec	+/-0.06 Nm	Per screw type,	  +/-0.06 Nm	  N/A 
  unless range stated	+/-0.5 in/lbs	see below	  +/-0.5 in/lbs(Note 6)
			
  Captive compression 
  connections, #4-40 hex
  (See note 1)
    low torque		0.34 Nm		Not Spec'd	  0.34 Nm	  No, tighten less 	
			3.0 in/lbs	Not Spec'd	  3.0 in/lbs	  than 6.0 in/lbs
    
    final torque	0.68 Nm		.58 - .73 Nm	  0.68 Nm(note 4) Yes
			6.0 in/lbs	5.2 - 6.5 in/lbs  6.0 in/lbs			
	
  Discrete M3 		0.8 Nm		.798 - .998 Nm	  0.8 Nm(note 4)  Yes
			7.0 in/lbs	7.0 - 8.8 in/lbs  7.0 in/lbs
 
  Discrete M5		3.76 Nm		3.76 - 4.70 Nm	  3.76 Nm	  Yes (See note 3)
			33.3 in/lbs	33.3-41.6 in/lbs  33.3 in/lbs						
				
			______________	_______________	  ______________  ____________________
			Orig. BSD Spec	Sun Spec	  Adj. BSD Spec	  Use of 6.0 in/lbs OK
			for Mfg. Build			  for Mfg. Build  In the Field
			______________	_______________	  ______________  ____________________
Specific components:
	
  Crkt Brkr, M3 	0.6 Nm		.798 - .998 Nm	  0.6 Nm(note 5)  Yes
			5 in/lbs	7.0 - 8.8 in/lbs  5 in/lbs
	
  Sys. board cover, M3	1.0 Nm		.798 - .998 Nm	  .798 - .998 Nm  Yes 
			8.9 in/lbs	7.0 - 8.8 in/lb	  7.0 - 8.8 in/lb
  I/O, Processor, 
  and Memory module 
  #4-40 hex
   captive,low torque	0.34 Nm 	Not Spec'd	  0.34 Nm	  No, tighten less 
	  		3.0 in/lbs	Not Spec'd	  3.0 in/lbs	  than 6.0 in/lbs
	
   captive,final torque	0.68 Nm 	.58 - .73 Nm	  0.68 Nm(note 4) Yes
	  		6.0 in/lbs	5.2 - 6.5 in/lbs  6.0 in/lbs
	
  I/O, Memory module, M3
   discrete screw 	0.8 Nm 		.798 - .998 Nm	  0.8 Nm(note 7)  Yes
	  		7.0 in/lbs	7.0 - 8.8 in/lb	  7.0 in/lbs
	
  Fan centerplane 
  torque, M3		0.6 Nm		.798 - .998 Nm	  0.6 Nm (Note 2) Yes
			5.3 in/lbs	7.0 - 8.8 in/lbs  5.3 in/lbs
	
  Centerplane torque,
    M5			3.76 Nm		3.76 - 4.70 Nm	  3.76 Nm	  Yes (See note 3)
			33.3 in/lbs	33.3-41.6 in/lbs  33.3 in/lbs				
				

Note 1: Manual erroneously indicates #2-56, this will be corrected 
	in the next rev.
Note 2: This is lower than the Sun spec because the screwhead will 
	be pressed against a circuit board.
Note 3: The 6.0 in/lbs preset tool can be used provided a specific 
	pattern is followed (TBD).
Note 4: Mechanical failures have been observed due to over-torquing 
	attached hardware.
Note 5: Attachment hardware is a thin piece of metal, higher torque 
	is not recommended.
Note 6: BSD will keep original range, but will state that if a range 
	is given it override this spec.
Note 7: In this application a higher spec is not recommended due to 
	the opposing hardware.


Sun Torque Spec Ranges:

Screw	   in/lbs	    Nm
	Min	Max	Min	Max

4-40	5.2	6.5	.58	.73
M3	7.0	8.8	.798	.998
M5	33.3	41.6	3.76	4.70  

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