Taken directly from the Panther Builders Manual

 

Rivet Options

 

Most of the rivet options on the Panther build are open and interchangeable.  There are some rivets requirements are not optional and are duly noted on the plans.  If the plans indicate “or equivalent” then the builder has the option of the rivet called out or an equivalent strength/grip length rivet according to the rivet manufacturer guidelines.  In general the builder can choose from:

·  Protruding Head pulled rivets

·  Flush/Countersunk pulled rivets. 

·  Flush aircraft rivets  - AD3

 

General Rivet Guidelines:

·  Rivet length is determined by the rivet grip guidelines of the rivet chosen.  Please follow the guidelines of the rivet manufacturer.

·  If the rivet is specified on the plans then use that rivet.  This is not optional.

·  If aluminum is attaching to steel then a stainless steel rivet is required.

·  Closed end rivets are used on the fuel tanks.

 

Understanding Rivet Nomenclature

SPA recommends the Cherry-N rivets.  The naming structure below is for the Cherry-N rivet.

Example rivet name commonly used in the Panther = BPSP-43

NOTE – you cannot use the A series rivets, as the shear strength is not high enough

 

First Letter   is the rivet material

Second   letter is mandrel material

Third   letter is head style

Fourth   letter is not always used

First   number is rivet diameter in 32nds of an inch:

Second   number is rivet maximum grip length in 16ths of an inch

B

B=5056   Aluminum

C=Stainless

(DO NOT USE   the rivet types below)

A=5052   Aluminum M=Monel S= Steel U=Copper

S

S = Steel,   C = Stainless

(DO NOT USE   the rivet types below)

A = 7178   Aluminum

P

P =   Protruding L = Large C = Flush

S

S =   Structural

4

4 = 4/32nds   or 1/8” diameter

 

3

1 = 1/16th   or .063 grip length

2 = 2/16ths   or 1/8th  (.125) grip   length

3 = 3/16ths   or .1875 grip length

4 = 4/16ths   or ¼ (.25) grip length

6 = 6/16ths   or 3/8th (.375) grip length

 

 

Determining Rivet Length Requirements

  To determine the proper grip length required add up each of the individual thickness of the metal being riveted to determine the total grip length required. 

Example:  If you are riveting a skin to a rib, and the skin in question is .020 and the rib is .025 the total required grip length is .045 and the proper rivet would be either a -41 length rivet. 

Example 2:  If you are riveting a spar channel (.032), and a spar stiffener (.1875) and a rib (.020) the total is .2395 and the proper rivet length is a – 44. 

SPA recommended blind rivet options include all of the below, if used in the proper grip length described above.

 

Blind Protruding head

Blind Flush/Countersunk

Stainless Protruding head

Stainless Flush/Countersunk

BSP(S) – 4x

BSC-4x

CCP-4x

CCC-4x

 

NOTE** - SPA LLC tested a great deal of rivets before settling on the ones chosen for the prototype.  We used flush/blind rivets on the skins where aesthetics are in question.  Where the rivets were not seen we used protruding heads such as BSP-41 or BSPS-43 according to grip length recommendations.  The recommended rivet for flush/blind for skin to rib attachment (except the fuel tanks) is the BSC-43 from ACS.  We use this to attach all of the skins on the Panther, and although it falls out of the typical grip range length, it produces tight joints and almost no stem pulls.  We recommend that any rivet you choose that you do a number of test installations verifying you result in a tight joint and minimal/no stem pulls.