I can not remove the object from my list DataTable

I am inside my service and here is where I put the parameter so that I receive the id of the row I want to delete.

@Transactional
public void eliminaHerramienta(Integer idherramienta) {
    try {
        Herramienta p = manager.find(Herramienta.class, idherramienta);
        manager.getTransaction().begin();
        manager.remove(p);
        manager.flush();
        manager.getTransaction().commit();
    } catch (Exception e) {
        manager.getTransaction().rollback();
        e.printStackTrace();
    } finally {
        manager.close();
    }
}

Then I'm in the controller to do the interaction with the view which is like a requestScoped

@Transactional
public void eliminar(Integer idherramienta) {
    System.out.println("entrando a eliminar alumno");
    herramientaService.eliminaHerramienta(idherramienta);

}

apparently everything is great but it does not go into the method of removing the moment when I click on the button to call that action on the controller.

    <p:dataTable value="#{herramientaAction.lstherramienta}" var="h"
        border="1" paginator="true" rows="5">
        <p:column>
            <f:facet name="header">Id</f:facet>
                        #{h.idherramienta}
                    </p:column>
        <p:column>
            <f:facet name="header">Nombre</f:facet>
                        #{h.name}
                    </p:column>
        <p:column>
            <f:facet name="header">stock</f:facet>
                        #{h.stock}
                    </p:column>
        <p:column>
            <f:facet name="header">precio</f:facet>
                        #{h.precio}
                    </p:column>
        <p:column>
            <f:facet name="header">fecha vencimiento</f:facet>
                        #{h.fecha}
                    </p:column>
        <p:column>
            <f:facet name="header">modelo</f:facet>
                        #{h.modelo.descripcion}
                    </p:column>

        <p:column>
            <p:commandButton id="btn1"
                action="#{herramientaAction.eliminar(h.idherramienta)}"   value="eliminar" />
        </p:column>
    </p:dataTable>

As you can see it has the view of a datatable, I do not know what thing I have to add to work or receive that action.