TASK 70-35-27-300-501 Installation Of Helical Coil Threaded Inserts

DMC:V2500-00-70-35-27-00A-920A-D|Issue No:001.00|Issue Date:2013-03-20

Export Control

EAR Export Classification: Not subject to the EAR per 15 C.F.R. Chapter 1, Part 734.3(b)(3), except for the following Service Bulletins which are currently published as EAR Export Classification 9E991: SBE70-0992, SBE72-0483, SBE72-0580, SBE72-0588, SBE72-0640, SBE73-0209, SBE80-0024 and SBE80-0025.

Copyright

© IAE International Aero Engines AG (2001, 2014 - 2021) The information contained in this document is the property of © IAE International Aero Engines AG and may not be copied or used for any purpose other than that for which it is supplied without the express written authority of © IAE International Aero Engines AG. (This does not preclude use by engine and aircraft operators for normal instructional, maintenance or overhaul purposes.).

Applicability

All

Common Information

TASK 70-35-27-300-501 Installation Of Helical Coil Threaded Inserts

Introduction

This procedure can be used to replace helical coil inserts (tanged or Tangless (R)) or repair damage to threads unless specified differently.

Helical coil threaded inserts are used both in initial part manufacture, which is typical for parts made of aluminum, and as a method to repair damage to threads.

Double helical coil threaded inserts are available for threads that have damage beyond the limits of standard helical coil thread insert specifications. See Figure.

Helical coil threaded inserts are available in all standard sizes in National Fine and National Coarse Series up to 1.5 inch (38.1 mm) size as well as 8 pitch threads, metric threads, and tapered pipe threads.

Over-sized helical coil threaded inserts can be used if the minimum wall thickness is kept.

Tangless inserts have advantages when compared to tanged inserts.

Tangless inserts do not have tangs to remove and discard, this helps prevent possible Foreign Object Damage (FOD).

Tangless inserts can reduce the time necessary for installation of threaded inserts.

NOTE

Tangless (R) is a registered trademark of ADVANEX, Inc. for helical coil inserts that do not have tangs.

NOTE

Other sources are permitted.

Preliminary Requirements

Pre-Conditions

NONE

Support Equipment

NONE

Consumables, Materials and Expendables

NONE

Spares

NONE

Safety Requirements

CAUTION

THE USE OF HELICAL COIL THREADED INSERTS IN THROUGH HOLES CAN CAUSE A LEAK PATH. THE USE OF AN APPLICABLE SEALANT AT THE BOLT HEAD INTERFACE (Fig. 70-35-27-990-003 ) IS RECOMMENDED.

Procedure

    1. SUBTASK 70-35-27-350-001 Procedure to Install Helical Coil Inserts

      1. To replace helical coil threaded inserts that were installed during the initial manufacture of the part, do the subsequent steps:

      1. Remove the helical coil threaded insert. Refer to the manufacturer's instructions.

      2. NOTE

        For applications up to 800 deg F (427 deg C), use stainless steel (AMS 7245) inserts.

        NOTE

        For applications at 800 to 1000 deg F (427 to 538 deg C), use Inconel X-750 (AMS 7246) inserts.

        To determine the correct size of the new insert, compare the new insert specifications with the initial finished thread hole size. Use the manufacturer's installation instructions as an aid in the correct insert selection.

        3. Treat the insert hole and other areas where it is possible the protective coating was removed. Do the subsequent procedure:

        1. For aluminum, refer to the SPM TASK 70-33-22-300-503 for the procedure to anodize touch-up the aluminum by brush or swab methods.

      4. Install the new helical coil threaded insert 0.75 to 1.5 pitch below the top surface. Refer to the manufacturer's instructions.

      5. NOTE

        If a Tangless insert is used, this step is not applicable.

        Break off the installation tang at the notch.

      6. Collect and remove all broken tangs so that there are none remaining with the part.

      2. To replace helical coil threaded inserts that were installed to repair damage to threads, do the subsequent steps:

      1. NOTE

        For applications up to 800 deg F (427 deg C), use stainless steel (AMS 7245) inserts.
        For applications at 800 to 1000 deg F (427 to 538 deg C), use Inconel X-750 (AMS 7246) inserts.
        To determine the correct size of the new insert, compare the new insert specifications with the initial finished thread hole size. Use the manufacturer's installation instructions as an aid in the correct insert selection.

        A sufficient wall thickness is necessary for the repair of damaged thread holes with helical coil inserts. Determine if there is sufficient wall thickness. See Figure.

      2. Drill and tap hole to the correct size. Refer to the manufacturer's instructions.

      3. Treat the insert hole and other areas where it is possible the protective coating was removed. Do the subsequent procedure:

      4. For aluminum, refer to the SPM TASK 70-33-22-300-503 for the procedure to anodize touch-up the aluminum by brush or swab methods.

      5. Install the new helical coil threaded insert 0.75 to 1.5 pitch below the top surface. Refer to the manufacturer's instructions.

      6. NOTE

        If a Tangless insert is used, this step is not applicable.

        Break off the installation tang at the notch.

      7. Collect and remove all broken tangs so that there are none remaining with the part.

      3. When it is necessary to use a double helical coil threaded insert to repair threads that have damage beyond the limits of standard helical coil threaded insert specifications, do the subsequent steps:

      1. NOTE

        For applications up to 800 deg F (427 deg C), use stainless steel (AMS 7245) inserts.

        NOTE

        For applications at 800 to 1000 deg F (427 to 538 deg C), use Inconel X-750 (AMS 7246) inserts.

        To determine the correct size of the new insert, compare the new insert specifications with the initial finished thread hole size. Use the manufacturer's installation instructions as an aid in the correct insert selection.

      2. A sufficient wall thickness is necessary for the repair of damage to thread holes with double threaded helical coil inserts. Determine if there is sufficient wall thickness. See Figure.

      3. Drill and tap hole to the correct size. Refer to the manufacturer's instructions.

        4. Treat the insert hole and other areas where it is possible the protective coating was removed. Do the subsequent procedure:

        1. For aluminum, refer to the SPM TASK 70-33-22-300-503 for the procedure to anodize touch-up the aluminum by brush or swab methods.

        5. Install the double helical coil threaded insert. Refer to the manufacturer's instructions.

        1. Install the outer insert 0.25 to 0.5 pitch below the top surface.

        2. Install the inner insert so that the end of the last coil is flush with the end of the outer insert. See Figure.

      6. NOTE

        If a Tangless insert is used, this step is not applicable.

        Break off the installation tang at the notch.

      7. Collect and remove all broken tangs so that there are none remaining with the part.

    2. Figure: Helical Coil Threaded Insert

    Helical Coil Threaded Insert

    Figure: Double Helical Coil Threaded Insert For Oversized Holes

    Double Helical Coil Threaded Insert For Oversized Holes

    Figure: Helical Coil Threaded Insert In Through Hole

    Helical Coil Threaded Insert In Through Hole

    Figure: Determination of Sufficient Wall Thickness For Parts Which Use Helical Coil Inserts For Thread Damage Repair

    Determination of Sufficient Wall Thickness For Parts Which Use Helical Coil Inserts For Thread Damage Repair

    Figure: Determination of Sufficient Wall Thickness For Parts Which Use Double Helical Coil Threaded Inserts For Thread Damage Repair

    Determination of Sufficient Wall Thickness For Parts Which Use Double Helical Coil Threaded Inserts For Thread Damage Repair

Requirements After Job Completion

Follow-On Conditions

NONE