Trimming composite mouldings using hand tools

URN: SEMMME235
Business Sectors (Suites): Mechanical Manufacturing Engineering Suite 2
Developed by: Enginuity
Approved: 2026

Overview

This standard identifies the competences you need to trim composite mouldings using hand tools, in accordance with approved procedures. You will be required to follow the appropriate instructions, drawings, specifications and documentation to trim various composite mouldings, using the correct trimming techniques.

You will be expected to select and use the correct tools and equipment for the trimming activity. You will trim a range of composite mouldings, incorporating a variety of features, by using cutting, sanding, drilling and polishing techniques and processes. Mouldings to be trimmed will include a range of resin and fibre materials.

Your responsibilities will require you to comply with organisational policy and procedures for the trimming activities undertaken, and to report any problems with the trimming activities, equipment or materials that you cannot personally resolve, or are outside your permitted authority, to the relevant people. You will be expected to work to instructions, with a minimum of supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you carry out.

Your underpinning knowledge will be sufficient to provide a good understanding of your work, and will provide an informed approach to applying composite moulding trimming techniques and procedures. You will have an understanding of the trimming techniques used, and their application, in adequate depth to provide a sound basis for carrying out the activities, recognising faults and ensuring the trimmed mouldings are to the required specification.

You will understand the safety precautions required when carrying out the trimming activities and when using the associated tools and equipment. You will be required to demonstrate safe working practices throughout, and will understand the responsibility you owe to yourself and others in the workplace.


Performance criteria

You must be able to:

P1    work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
P2    follow relevant specifications for the moulding to be trimmed
P3    obtain the appropriate tools and equipment for the shaping operations and check they are in a safe and usable condition
P4    carry out any required preparation activities prior to undertaking the trimming operation
P5    trim the moulding using appropriate methods and techniques
P6    check that all the required shaping operations have been completed to the required specification
P7    complete and store all relevant documentation in accordance with organisational requirements
P8    deal with problems within your control and report those that cannot be solved


Knowledge and Understanding

You need to know and understand:

K1    how to work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
K2    the importance of wearing the appropriate personal protective equipment (PPE), and of keeping the work area clean and tidy
K3    the application of COSHH regulations in relation to the storage, use and disposal of composite materials and consumables
K4    the specific environmental conditions that must be observed when trimming composite mouldings
K5    the importance of setting up and using dust control measures including segregated work areas, dust extraction and working practices 
K6    how to extract and use information from engineering drawings and related specifications in relation to work undertaken
K7    how to interpret drawings, imperial and metric systems of measurement, work piece reference points and system of tolerance
K8    how to prepare for the trimming activities, and how to mark out the mouldings for the material that needs to be removed
K9    quality procedures used in the workplace to ensure production control and the completion of such documents
K10    conventions and terminology used for trimming activities 
K11    the different types of manual and power tools used in composite trimming operations
K12    how the type of material being trimmed can affect the selection of cutting media, tools and speeds
K13    the different types of cutting tools and abrasives used in trimming composite materials, and their application
K14    the visual identification of cured and non-cured composite materials
K15    the identification of defects in composite mouldings
K16    the methods used in the trimming of composite mouldings
K17    the sequence to be followed when preparing for trimming activities
K18    the care and safe handling of composite mouldings throughout the trimming cycle
K19    the extent of your own responsibility and to whom you should report if you have problems that you cannot resolve


Scope/range


Scope Performance

1.    Carry out all of the following during the trimming activities:
1.1    obtain and use the appropriate documentation (such as job instructions, drawings, quality control documentation, material data sheets)
1.2    adhere to procedures or systems in place for risk assessment, personal protective equipment and other relevant safety regulations and procedures to realise a safe system of work
1.3    obtain the correct tools and equipment for the activity and ensure they are safe to use
1.4    follow safe and appropriate trimming techniques and working practices at all times
1.5    segregate and dispose of waste materials using the correct procedure
1.6    return all tools and equipment to the correct location on completion of the trimming activities
1.7    leave the work area in a safe and suitable condition on completion of the activities

2.    Carry out all of the following when preparing for the trimming activity:
2.1    check the moulding is correct and complete
2.2    check for any defects in the moulding
2.3    identify and protect the moulding in the work area

3.    Mark out the mouldings using two of the following methods:
3.1    scriber            
3.2    moulded scribe lines  
3.3    trimming templates
3.4    height gauge                   
3.5    centre punch
3.6    scribing jigs
3.7    other specific method

4.    Cut mouldings using two the following methods:
4.1    cutting wheels/discs
4.2    routers
4.3    saws                 
4.4    trim jigs

5.    Sand mouldings using two of the following methods:
5.1    rubbing blocks  
5.2    pencil grinders
5.3    belt sanders
5.4    diamond files       
5.5    disc sanders
5.6    orbital sanders

6.    Use a hand drill or pedestal drill to drill mouldings using one of the following methods:
6.1    drill jigs             
6.2    counterbores 
6.3    drill bits
6.4    hole saws         
6.5    countersinks

7.    Polish mouldings using two of the following methods if final finish is required:
7.1    wet sanding            
7.2    polishing compound     
7.3    orbital sander
7.4    cutting compound  
7.5    rubbing block 
7.6    polisher

8.    Trim mouldings using techniques for one of the following resin types:
8.1.    bio resin
8.2.    thermoplastic
8.3.    polyester
8.4.    vinyl ester
8.5.    epoxy
8.6.    phenolic
8.7.    bismaleimide
8.8.    cyanate ester
8.9.    other (to be specified)

9.    Trim mouldings using techniques for one of the following fibre types:
9.1.    natural fibre
9.2.    thermo plastic
9.3.    glass
9.4.    aramid
9.5.    carbon
9.6.    hybrid
9.7.    other specific types

  1.     Trim mouldings that require, or incorporate five of the following features:
    10.1    straight edges        
    10.2    multiple holes
    10.3    curved edges       
    10.4    multiple hole sizes
    10.5    flat surfaces           
    10.6    countersinks
    10.7    polished surfaces    
    10.8    counterbores
    10.9    shaped surfaces       
    10.10  further lay-up stages
    10.11  radius corners      
    10.12  inserts to be drilled
    10.13  returns              
    10.14  inserts to be tapped
    10.15  net edges         
    10.16  solid cores
    10.17  joggle details    
    10.18  honeycomb cores
    10.19  removal of join lines 
    10.20  edge filling/sealing

11.    Trim a range of mouldings in compliance with one of the following standards:
11.1    BS, ISO or BSEN standards and procedures
11.2    customer standards and requirements
11.3    organisational standards and procedures
11.4    recognised compliance agency/body standards


Scope Knowledge


Values


Behaviours


Skills


Glossary


Links To Other NOS


External Links


Version Number

3

Indicative Review Date

2029

Validity

Current

Status

Original

Originating Organisation

Enginuity

Original URN

SEMMME2-35

Relevant Occupations

Engineering, Engineering and Manufacturing Technologies, Engineering Technicians

SOC Code

3113

Keywords

engineering; manufacturing; mechanical; manual trimming; composite moulds; methods; techniques; equipment; sanding; polishing